Developing cost-effective and mechanistically understood non-precious metal electrocatalysts for the ammonia oxidation reaction (AOR) is essential for sustainable hydrogen production. Herein, we report a scalable solution-phase strategy and versatile platform to synthesize (5-6 nm) Ni/Cu hydroxide nanoparticles and their trimetallic variants (Ni/Cu/X) with precisely tunable compositions, enabling systematic exploration of composition-activity relationships. The optimized catalyst Ni containing 20 mol% Cu delivers a current density of 42 mA cm-² at 0.55 V vs. Ag/AgCl in alkaline electrolyte, significantly outperforming Cu-free Ni(OH)₂. Spectroscopic analyses reveal the formation of a Ni1-xCuₓOOH active phase with modified local coordination under electrochemical conditions. Density functional theory (DFT) calculations reveal that Cu exerts a dual role during AOR. Moderate Cu incorporation facilitates OH-vacancy formation and lowers the barrier for N-N coupling, whereas excessive Cu suppresses NH₃ activation by increasing the thermodynamic penalty of the first deprotonation step. The resulting balance between Cu-assisted coupling and Ni-mediated substrate activation explains the experimentally observed volcano-type activity trend and provides insight into the design of non-precious AOR electrocatalysts.

Efficiently utilizing ammonia (carbon-free fuel) via low-temperature fuel cells is severely hindered by the sluggish kinetics of ammonia oxidation reaction (AOR). Herein, platinum-iridium-tungsten nanocubes (PtIrW-NCBs) with exposed {1 0 0}-rich facets were synthesized by a glucose-assisted solvent-thermal method, in which alloying W not only can facilitate the formation of such specific nanostructures to expose more active sites for AOR, but also modulate the electronic structure of PtIr to promote the kinetics of AOR. The PtIrW-NCBs featuring the small nanoparticle size of 5.05 +/- 0.07 nm exhibit superior AOR performance, wherein the onset potential is down to 0.319 V and the mass activity is 30.15 A g 1 (PGM= Pt, Ir) at 0.50 V vs. RHE, significantly higher than those of reported majority of AOR catalysts and even commercial PtIr/C. Meanwhile, in situ Fourier transform infrared spectroscopy measurement further reveals that AOR on PtIrW-NCBs dominantly undergoes the dimerization path of NHx (1 x 2). In addition, the theoretical calculations also identify that alloying W into PtIr can contribute additional electrons to 5d orbitals of PtIr, enabling the d-band center approaching the Femi level, which in turn induces the high-filling of bonding orbitals of N-N bond in *N2H4, promoting the dimerization of *NH2 to *N2H4 and thus leading to high AOR activity of PtIrW. This work provides new insights for designing efficient AOR electrocatalysts. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

While the Water-Gas Shift (WGS) reaction plays a crucial role in hydrogen production for fuel cells, finding suitable catalysts to achieve high yields for low-temperature WGS reactions remains a persistent challenge. Artificial Intelligence (AI) has shown promise in accelerating catalyst design by exploring vast candidate spaces, however, two key gaps limit its effectiveness. First, AI models primarily train on numerical data, which fail to capture essential text-based information, such as catalyst synthesis methods. Second, the cross-disciplinary nature of catalyst design requires seamless collaboration between AI, theory, experiments, and numerical simulations, often leading to communication barriers. To address these gaps, we present AceWGS, a Large Language Models (LLMs)-aided framework to streamline WGS catalyst design. AceWGS interacts with researchers through natural language, answering queries based on four features: (i) answering general queries, (ii) extracting information about the database comprising WGS-related journal articles, (iii) comprehending the context described in these articles, and (iv) identifying catalyst candidates using our proposed AI inverse model. We presented a practical case study demonstrating how AceWGS can accelerate the catalyst design process. AceWGS, built with open-source tools, offers an adjustable framework that researchers can readily adapt for a range of AI-accelerated catalyst design applications, supporting seamless integration across cross-disciplinary studies.

Hydrogen is a critical clean energy carrier in future energy systems, and developing greener production pathways is essential. In support of Singapore's National Hydrogen Strategy, this study assesses the environmental impacts and damages associated with hydrogen production via a methane membrane pyrolysis system and conventional methane steam reforming in Singapore using life cycle assessment (LCA). The analysis covers natural gas extraction, pipeline transportation, process operations, by-products' production, and key emissions within defined system boundaries. Results indicate that the membrane pyrolysis scenario has environmental advantages due to the co-production of valuable carbon materials, while the conventional steam reforming process leads to significantly higher emissions for the water consumption and the energy consumption for the capture of the yielded CO2. The global warming potential (GWP) for producing 1 kg of hydrogen is estimated at 2.22 kg CO2 eq for the membrane pyrolysis system and 6.18 kg CO2 eq for the steam reforming process. Environmental damage assessment shows single scores of-26.28 mPt and 115.66 mPt for the pyrolysis and reforming scenarios, respectively, indicating an overall environmental benefit for the former. These findings offer valuable insights for strategic decision-making toward sustainable hydrogen production in Singapore and beyond.

This study assesses the techno-economic viability of a palladium-based membrane reactor for catalytic decomposition (pyrolysis) of methane. A process simulation approach is employed to evaluate the reactor's performance and to design a complete catalytic decomposition plant. The membrane-based process is benchmarked against conventional steam methane reforming (SMR) in terms of the levelized cost of hydrogen (LCOH) production. Results indicate that the membrane reactor process achieves an approximately 5% lower LCOH than SMR, primarily due to reduced capital costs and the elimination of carbon capture and storage (CCS) requirements. Additionally, the recovery and sale of valuable carbon byproducts-such as carbon black-further improve the economic feasibility of the process. From an environmental perspective, the membrane process presents a cleaner alternative by avoiding CO2 emissions and generating solid carbon instead. Overall, the palladium-based membrane reactor demonstrates strong potential as a transitional pathway toward more sustainable hydrogen production.

Plasma catalysis technology is emerging as a promising approach for addressing energy and environmental challenges in sustainability. This review provides an overview of plasma technology and summarizes recent advances in plasma catalysis from both experimental and theoretical perspectives. Current laboratory-scale studies have demonstrated the versatility of plasma catalysis in various processes, including carbon conversion, hydrogen production, and the removal of volatile organic compounds. The inherently complex environment of plasma catalysis requires in situ characterization and theoretical modeling to elucidate the underlying reaction mechanisms, which in turn guide the rational design of efficient catalysts and optimized reactor configurations. These advances are vital for enhancing the economic feasibility and accelerating the commercialization of this technology. Nevertheless, the scale-up and practical deployment of plasma-catalytic systems from laboratory to industrial scales remain challenging. In this review, we critically examine the current state of plasma catalysis research and its applications across a wide range of reactions. Particular attention is given to in situ mechanistic studies, reactor design, catalyst development, process scale-up, and theoretical modeling. Finally, we provide a forward-looking perspective on the opportunities and future directions to address existing challenges and harness the potential of plasma catalysis toward sustainable development.

Catalytic decomposition and non-oxidative coupling of methane (CDM and NOCM) driven by plasma, especially non-thermal plasma, have been determined as strategic means for sustainable production of COx-free hydrogen and value-added chemicals. The ‘one-step’ direct CDM and NOCM bypass the need for intermediate syngas production to hydrogen and chemicals using the Fischer–Tropsch process, thus benefiting from energy savings, but nevertheless, are still plagued by poor yields and stability. Thermal, warm, and non-thermal plasma technologies have gained research momentum due to the efficacy for activation of strong C–H chemical bonds in methane. Herein, the current literature is firstly reviewed to elucidate the mechanistic insights and plasma synergies (with and without catalysts) for COx-free H2 production via methane conversion with a particular focus on CDM and NOCM reactions. Our review ascertains that while plasma-assisted methane activation can resolve the need for high energy activation and dissociation of C–H bonds, the governing reaction pathways and difficulties in tuning product selectivity with plasma alone warrant further research on the role of plasma-catalysis as a promising solution to tune reaction selectivity. Additionally, we explore strategies for catalyst design and the selection of plasma sources to improve synergistic interactions in plasma-catalysis. Selected examples of catalyst use and reactor design in plasma-catalytic setups are presented. Finally, drawing from recent advancements and our research perspective, an advanced plasma integrated system is proposed, especially a concept for a plasma-catalytic reactor featuring a membrane separator, which may serve as an effective unit for hydrogen production and purification.

Platinum-based supported intermetallic alloys (IMAs) demonstrate exceptional performance in catalytic propane dehydrogenation (PDH) primarily because of their remarkable resistance to coke formation. However, these IMAs still encounter a significant hurdle in the form of catalyst deactivation. Understanding the complex deactivation mechanism of supported IMAs, which goes beyond conventional coke deposition, requires meticulous microscopic structural elucidation. In this study, we unravel a nonclassical deactivation mechanism over a PtZn/γ-Al 2 O 3 PDH catalyst, dictated by the PtZn to Pt 3 Zn nanophase transformation accompanied with dezincification. The physical origin lies in the metal support interaction (MSI) that enables strong chemical bonding between hydroxyl groups on the support and Zn sites on the PtZn phase to selectively remove Zn species followed by the reconstruction towards Pt 3 Zn phase. Building on these insights, we have devised a solution to circumvent the deactivation by passivating the MSI through surface modification of γ-Al 2 O 3 support. By exchanging protons of hydroxyl groups with potassium ions (K) on the γ-Al 2 O 3 support, such a strategy significantly minimizes the dezincification of PtZn IMA via diminished metal-support bonding, which dramatically reduces the deactivation rate from 0.2044 to 0.0587 h −1 . These findings decode the nonclassical PDH deactivation mechanism over supported IMA catalysts and elaborate a new logic for the design of high-performance IMA based PDH catalysts with long-term stability.

The development of catalysts for low-temperature methane combustion is crucial in addressing the greenhouse effect. An effective industrial catalyst strategy involves optimizing noble metal utilization and boosting metal–metal interaction. Here, the PdNi-H catalyst was synthesized using the self-assembly method, achieving the high dispersion and close proximity of Pd and Ni atoms compared to the counterparts prepared by the impregnation method, as confirmed by EDS mapping. The XRD and TEM results revealed Pd2+ and Ni2+ doping within the CeO2 lattice, causing distortions and forming Pd-O-Ce or Ni-O-Ce structures. These structures promoted oxygen vacancy formation in CeO2, and this was further confirmed by the Raman and XPS results. Consequently, the PdNi-H catalyst demonstrated an excellent redox ability and catalytic activity, achieving lower ignition and complete methane burning temperatures at 282 and 387 °C, respectively. The highly dispersed PdNi species played a pivotal role in activating methane for enhanced redox ability. Additionally, the narrow size distribution range contributed to more vacancies on the surface of CeO2, as confirmed by the XPS results, thereby facilitating the activation of gas phase oxygen to form oxygen species (O2−). This collaborative catalytic approach presents a promising strategy for developing efficient and stable methane combustion catalysts at low temperatures.

Efficiently utilizing ammonia (carbon-free fuel) via low-temperature fuel cells is severely hindered by the sluggish kinetics of ammonia oxidation reaction (AOR). Herein, platinum-iridium-tungsten nanocubes (PtIrW-NCBs) with exposed {1 0 0}-rich facets were synthesized by a glucose-assisted solvent-thermal method, in which alloying W not only can facilitate the formation of such specific nanostructures to expose more active sites for AOR, but also modulate the electronic structure of PtIr to promote the kinetics of AOR. The PtIrW-NCBs featuring the small nanoparticle size of 5.05 ± 0.07 nm exhibit superior AOR performance, wherein the onset potential is down to 0.319 V and the mass activity is 30.15 A g−1(PGM= Pt, Ir) at 0.50 V vs. RHE, significantly higher than those of reported majority of AOR catalysts and even commercial PtIr/C. Meanwhile, in situ Fourier transform infrared spectroscopy measurement further reveals that AOR on PtIrW-NCBs dominantly undergoes the dimerization path of NHx (1 ≤ x ≤ 2). In addition, the theoretical calculations also identify that alloying W into PtIr can contribute additional electrons to 5d orbitals of PtIr, enabling the d-band center approaching the Femi level, which in turn induces the high-filling of bonding orbitals of N–N bond in *N2H4, promoting the dimerization of *NH2 to *N2H4 and thus leading to high AOR activity of PtIrW.This work provides new insights for designing efficient AOR electrocatalysts.

The Modified Fischer-Tropsch process converts CO2 to chemicals using a dual-function Fe-based catalyst composed typically of magnetite and iron carbides. However, catalyst deactivation limits its industrial application. In this study, we combined Density Functional Theory (DFT) calculations and experiments to provide insights into the underlying catalyst deactivation and regeneration mechanisms. The dynamic state of the catalyst was observed with time on stream, revealing the impact of the evolving reaction mixture along the reactor. Rapid CO2 and H2O dissociation on the carbide phase creates persistent *O, causing Fe5C2 deactivation through oxidation. On the other hand, the direct carburization of Fe3O4 proves challenging due to significant energy barriers, underscoring the need for metallic Fe or a highly reduced surface as a precursor to effective catalyst activation. These insights into iron catalyst evolution during CO2 reduction can guide the development of strategies for achieving efficient catalyst performance.

We present a detailed DFT-based mechanistic investigation of syngas conversion mechanism over Co-4 cluster grafted onto HZSM-5 zeolite, [Co4H], employing a QM/MM embedded cluster approach. Starting from the [Co4H] complex, our results show that a favorable coordination of CO over H-2, followed by CO hydrogenation leads to a stable -CH2O complex, [Co-4(CH2O)(H)]. Coordination of a second CO molecule to [Co-4(CH2O)(H)] complex, followed by CH2-O bond activation, and subsequent removal of CO as CO2 results in the formation of crucial methylene complex [Co-4(CH2)(H)], serving as a branching point for the pathways leading to methane, ethene, and ethane. On the pathway to ethene formation, coordination of a third CO molecule to [Co-4(CH2)(H)] complex yields the active [Co-4(CH2)(CO)(H)] complex, which is 16.0 kcal mol(-1) more stable than the methyl complex [Co-4(CH3)] on the pathway to methane. From the active species [Co-4(CH2)(CO)(H)], we demonstrate that the pathways to both methane and ethene are competing in nature, with the -CH3 hydrogenation barrier, 35.1 kcal mol(-1), is lower by only 1.3 kcal mol(-1) than the competing C-O bond activation barrier on the pathway to ethene, 36.4 kcal mol(-1). However, the significant stability of the active species [Co-4(CH2)(CO)(H)] effectively compensates for this minor difference in barriers, ultimately favoring the formation of ethene over methane. Finally, the ethene desorption barrier is 4.1 kcal mol(-1) lower than the ethene hydrogenation barrier on the pathway to ethane, indicating the ease of ethene removal from the system. Overall, our DFT study describes that the syngas conversion mechanism catalyzed by [Co4H] system produces ethene selectively via 4CO+2H(2)-> C2H4+2CO(2).

This study reports boosting the catalytic activity for CO2 methanation at low temperatures (<300 degrees C) through construction of hollow Ni/CeO2 and modulation of Ni-CeO2 interaction by calcination. Hollow Ni/CeO2 catalysts exhibit smaller Ni and CeO2 nanoparticles, leading to an increased number of Ni-CeO2 interfaces, improved hydrogen spillover, increased oxygen vacancy concentration, and exclusive weak basic sites, indicating different metal-support interaction strengths compared to conventional Ni/CeO2. DFT calculation and CO2-TPD reveal that CO2 over the hollow Ni/CeO2 catalyst can be adsorbed and dissociated into CO* at the Ni-CeO2 interface with surrounding oxygen vacancies. In-situ DRIFTS analysis reveals an enhanced CO* pathway on hollow Ni/ CeO2. These factors lead to enhanced catalytic activity at low temperatures, with a high CO2 conversion (64.1%) at 225 degrees C, significantly higher than Ni/CeO2 and most previously reported catalysts. In essence, this work provides an effective approach to constructing high-performance, low-temperature methanation Ni-based catalysts.

Machine learning (ML) has widespread applications in catalyst discovery and reaction optimization. We present a theory‐guided machine learning framework to evaluate the carbon monoxide (CO) conversion performance of noble metal catalysts in water‐gas shift (WGS) reaction. Our study is based on an open source WGS dataset, which we modify significantly to be consistent with the chemical reaction principles. We apply state‐of‐the‐art ML models including artificial neural networks, extreme gradient boosting to predict CO conversion percentage. These models show superior regression performance than the previously reported results in the literature. We further generalize the existing data structure by including physical, chemical and surface chemistry properties as fingerprint features that rationalize the importance of all the input features for CO conversion. We noticed that purely data‐driven ML models frequently violate the thermodynamic equilibrium principle and predict unphysical CO conversion percentage. We address these two problems by developing a custom loss function and an additional activation function in our neural networks architecture. Our proposed theory‐guided ML model displays high accuracy (R2 score is 0.95 and root mean square error is 6.87) and physically robust predictions. The model also opens up promising possibilities to improve CO conversion percentage, which were previously unexplored in experiments.

Metal promotion is the most widely adopted strategy for enhancing the hydrogenation functionality of an oxide catalyst. Typically, metal nanoparticles or dopants are located directly on the catalyst surface to create interfacial synergy with active sites on the oxide, but the enhancement effect may be compromised by insufficient hydrogen delivery to these sites. Here, we introduce a strategy to promote a ZnZrO x methanol synthesis catalyst by incorporating hydrogen activation and delivery functions through optimized integration of ZnZrO x and Pd supported on carbon nanotube (Pd/CNT). The CNT in the Pd/CNT + ZnZrO x system delivers hydrogen activated on Pd to a broad area on the ZnZrO x surface, with an enhancement factor of 10 compared to the conventional Pd-promoted ZnZrO x catalyst, which only transfers hydrogen to Pd-adjacent sites. In CO 2 hydrogenation to methanol, Pd/CNT + ZnZrO x exhibits drastically boosted activity—the highest among reported ZnZrO x -based catalysts—and excellent stability over 600 h on stream test, showing potential for practical implementation.

Various types of carbon catalysts are investigated for the oxidative desulfurization (ODS) of dibenzothiophene in the presence of hydrogen peroxides as oxidants. The catalytic performance of graphene nanoplatelets (GNPs) outperform other carbon catalysts, and it can be further boosted by ultrasonication to achieve up to 96% sulfur removal. Through parametric studies of the graphene nanoplatelet catalysts, the removal of sulfur occurs via both strong physical adsorption (-50%) and chemical oxidative desulfurization routes (-32-43%). Modifications of graphene nanoplatelets by ball milling, chemical activation, CO2 gasification and H2SO4-acid treatment have significant effects on the catalytic performance. The H2SO4-acid treatment improves 10% of the sulfur removal and enriches the carbonyl (C = O) functional groups on the GNP catalysts. Only a minor loss of 7% in the ODS performance when the GNP catalysts were reused 3 times. Strong adsorption (-1.49 eV to -2.96 eV) of thiophene model occurs at the planar and armchair edges, while chemisorption (-6.59 eV) at the zigzag edges of GNP catalysts as supported by density functional theory simulations.

While iron carbide catalysts are widely used to produce diverse hydrocarbons during Fisher-Tropsch syn-thesis, the complexity of the catalyst and reaction makes it very challenging to obtain a deep understand-ing of the chemical process and to further improve the performance. In this work, we propose a novel mechanism through density functional theory simulations for CO-derived surface C hydrogenation to C2H4 involving previously unexplored surface diffusion of partially hydrogenated intermediates (CH, CHCH), which significantly reduces the effective energy barrier (Ea-eff) of CH2CH2 from 2.89 eV to 2.10 eV. The hydrogenation of CH2CH to C2H4 is the key step of the entire process. Studies on the corre-lation between the average Bader charge of surface Fe and the Ea-eff of CH4 and CH2CH2 formation indicate that an increase in the positive charge of iron can enhance the activity and selectivity (with reference to CH4) of ethylene formation.(c) 2023 Elsevier Inc. All rights reserved.

Ethanol steam reforming (ESR) is an attractive way to produce renewable H2 and has been intensely studied. An iron promoted Ir catalyst IrFe/Al2O3 is reported for the first time to show better performance than Ir/Al2O3 in ESR and the structural change in the IrFe/Al2O3 catalyst under realistic ESR conditions is investigated. IrFe alloy is observed after reduction in H2. However, the IrFe alloy is disrupted during ESR because of an adsorption-induced structural change. Ir appears in metallic-like state while Fe exists as partially reduced FexOy under the reaction condition. The active center is therefore IrFexOy instead of IrFe alloy. The discovery of the transformation of IrFe alloy to IrFexOy during ESR deepens the understanding of the dynamic behaviour of IrFe catalyst and provides a correlation between the catalyst structure and catalytic performance.

Thestructure of the catalyst precursor and controlled sinteringof nickel nanoparticles govern the activity of nickel phyllosilicatesfor low-temperature methane decomposition. Catalytic methane decomposition (CMD) is a promisingtechnologyfor large-scale production of CO (x) -freeH(2) from natural gas that can also produce valuable carbonbyproducts. Although equilibrium conversions and reaction rates ofCMD generally increase with temperature, operation in a low-temperatureregime with simultaneous H-2 recovery could potentiallylead to operating cost and energy savings. Here, we report that well-dispersedNi-SiO2, derived from high-temperature reductionof nickel phyllosilicates, is active for CMD at temperatures below500 degrees C, with initial H-2 production rates of up to5.3 mol H-2/g(cat)center dot h at 25% CH4 conversion. This ability to achieve rates comparable to other well-establishedcatalysts is contrary to expectations that small (<ca. 10 nm) Ninanoparticles are inactive for CMD because of rapid deactivation andattributed here to an unusual mobility of nickel-silica interfacesin the presence of CH4 that leads to controlled sinteringof the originally well-dispersed Ni nanoparticles. We further showthat the ratio of 1:1 and 2:1 nickel phyllosilicates in the precursor,which governs catalyst reducibility and can be tuned by adding NH4F to the synthesis mixture, is a key descriptor of catalyticperformance. Our findings provide valuable insight into catalyst andprocess design for low-temperature CMD.