With the escalating severity of climate change, DRM reaction has gained attention as an effective pathway for utilizing CO2. This work focuses on typical Ni nanoparticles to emphasizes the impact of nanoparticle size on the activity and stability of the DRM reaction. Based on DFT theoretical calculations, a systematic analysis of the adsorption energies and reaction mechanisms on the (111), (100), and (211) surfaces of the nanoparticles were conducted. It was found that the energy barrier of the DRM reaction is primarily influenced by the binding strength. The dissociation of CH4 is mainly associated with C*-H* bonds, while the decomposition of CO2 is related to C*-O* bonds. Through microkinetic analysis combined with Wulff theory, the variation trend of catalytic activity with temperature for different nanoparticle sizes was further investigated, revealing that nanoparticles smaller than 3 nm exhibit higher activity. Based on the reaction mechanism a catalyst screening method was proposed. This work aims to provide important theoretical guidance for the optimization design of DRM catalysts by examining the effects of nanoparticle size on catalytic activity and stability.

Preparation and characterization of a novel interlayer expanded zeolite with a 12 × 12-ring structure.

The dry reforming of methane plays a vital role in carbon recycling. However, despite their high activity, Ni catalysts are susceptible to deactivation caused by the deposition of carbon. Co-doped Ni catalysts can address this issue, but the doping ratio has obvious effect on the activity. In this study, we utilized density functional theory calculations and microkinetic model simulations to gain insight into how Co doping affects both carbon deposition resistance and Ni catalytic activity. By analyzing the reaction mechanism, we discovered that the concentration of surface O* significantly influences the deactivation of carbon deposition on the surface of Ni-based catalysts. An appropriate concentration of O* can reduce the occupation of CC* sites, while excessive O* results in surface poisoning and reduced H2 production rates. We propose that the anti-carbon deposition performance of Ni catalysts can be improved by modulating the CH4/CO2 inlet ratio appropriately. Our findings provide valuable guidance for rational design of effective DRM catalysts.

In this study, reaction mechanism of the electrocatalytic reduction of CO2 to C2H5OH over the Si/Cu(111) surface were systematically investigated by using the first-principles calculations. The results show that the introduction of oxyphilic Si atom into Si/Cu(111) surface forms the Siδ+-(Cu6)δ- configuration, which can effectively adsorb CO2 with a considerable adsorption energy. The adsorbed CO2 could be reduced to CO by a unique dissociation adsorption process induced by the aerobic Si center. Compared to the original Cu(111) surface, the introduction of a Si atom is thermodynamically and kinetically beneficial for the dimerization of CO. The presence of an oxyphilic Si atom on the Cu(111) surface can effectively improve the selectivity for ethanol products by forming Si-O bonds on the hydrogenation pathway.

With the escalating severity of climate change, the DRM reaction has gained attention as an effective pathway for utilizing CO2. Enhancing reaction activity and identifying the sources of carbon deposition during the DRM reaction on Ni-based catalysts pose crucial yet challenging questions. In this study, we investigate the effects of Mo doping on the reaction activity and carbon deposition of Ni catalysts using a combined DFT and microkinetic method. In terms of the models, Mo replaced one Ni atom in the surface and subsurface layers to represent Mo in the initial stages and in prolonged on the reaction, namely NiMoU(211) and NiMoL(211). Through the analysis of electronic structure, intermediate structures, and reaction barriers compared with Ni(211), the impact of Mo doping on the surface activity and carbon deposition of Ni(211) is studied. The results indicate that the strong Ni-Mo interaction enhances intermediate stability, leading to increased reaction activity. Mo doping promotes the increase in O concentration, but at low temperatures, reaction rates decrease sharply. Furthermore, Mo doping enhances the resistance to carbon deposition on Ni(211) surfaces and improves the ability to remove carbon deposits, especially in prolonged reaction models. These findings provide new mechanistic insights into the DRM reaction on Ni(211) surfaces, which were previously well-explained by experimental results, and are valuable for understanding quantum processes.

With the escalating severity of climate change, the DRM reaction has gained attention as an effective pathway for utilizing CO2. Enhancing reaction activity and identifying the sources of carbon deposition during the DRM reaction on Ni-based catalysts pose crucial yet challenging questions. In this study, we investigate the effects of Mo doping on the reaction activity and carbon deposition of Ni catalysts using a combined DFT and microkinetic method. In terms of the models, Mo replaced one Ni atom in the surface and subsurface layers to represent Mo in the initial stages and in prolonged on the reaction, namely NiMoU(2 1 1) and NiMoL(2 1 1). Through the analysis of electronic structure, intermediate structures, and reaction barriers compared with Ni(2 1 1), the impact of Mo doping on the surface activity and carbon deposition of Ni(2 1 1) is studied. The results indicate that the strong Ni-Mo interaction enhances intermediate stability, leading to increased reaction activity. Mo doping promotes the increase in O concentration, but at low temperatures, reaction rates decrease sharply. Furthermore, Mo doping enhances the resistance to carbon deposition on Ni(2 1 1) surfaces and improves the ability to remove carbon deposits, especially in prolonged reaction models. These findings provide new mechanistic insights into the DRM reaction on Ni(2 1 1) surfaces, which were previously well-explained by experimental results, and are valuable for understanding quantum processes.

A method for introducing heteroatoms Al, Ti, and Sn into the framework of FER-type zeolite was provided. The incorporation of heteroatoms was achieved by intercalation of sub-zeolite of lamellar precursor PLS-3 that possessed disordered structure along layered direction using 4-amion-2,2,6,6-tetramentylniperidine together with salts containing a heteroatom. During intercalation, the molar ratio of Si and heteroatoms can be adjusted between 30 to ∞. Heteroatoms entered the material with the help of hydrothermal synthesis conditions used in the intercalation process, resulting in reordered layered metalosilicate structure. After mild acid treatment of these metalosilicates to remove extra-framework heteroatoms and further calcination, we obtained a three-dimensional zeolite of FER topology with framework Al, Ti, and Sn.

•Linear relationships between activation energy and reaction entropy was identified.•Reaction pathways of methane reforming reaction on Ni3Co (111) surface were obtained.•Mechanism of carbon deposition on Ni3Co (111) surface was revealed in detail.•Anti-coking strategies on methane reforming reaction were proposed.

The fluorescent molecules utilizing hybridized local and charge-transfer (HLCT) state as potential organic light-emitting diodes materials attract extensive attention due to their high exciton utilization. In this work, we have performed the density functional theory method on three HLCT-state molecules to investigate their excited-state potential energy surface (PES). The calculated results indicate the T 1 and T 2 energy gap is quite large, and the T 2 is very close to S 1 in the energy level. The large gap is beneficial for inhibiting the internal conversion between T 1 and T 2 , and quite closed S 1 and T 2 energies are favor for activating the T 2 → S 1 reverse intersystem crossing path. However, considering the singlet excited-state PES by twisting the triphenylamine (TPA) or diphenylamine (PA) group, it can be found that the TPA or PA group almost has no influence on T 1 and T 2 energy levels. However, the plots of S 1 PES display two kinds of results that the S 1 emissive state is dominated by charge-transfer (CT) or HLCT state. The CT emission state formation would decrease the S 1 energy level, enlarge the S 1 and T 2 gap, and impair the triplet exciton utilization. Therefore, understanding the relationship between the S 1 PES and molecular structures is important for designing high-performance luminescent materials utilizing HLCT state.

The charge carrier excitation–recombination process between the donor and acceptor, and the photocatalytic reduction of CO2to CO over CN based DA composites.

A P-CN/CsPbBr3 photocatalyst with a lamellar porous structure was prepared by a high temperature calcination and freeze drying method, and it exhibited superior CO2 reduction performance under the conditions of full spectrum irradiation.

A series of extra-large micropore Sn-zeolites with different Si/Sn ratios is post-synthesized by treating the interlayer-expanded material ECNU-9-cal773 with a solution of HCl containing NH4F and SnCl4∙5H2O, named as IEZ-Sn-PLS-3(S4R). During treatment, HCl, NH4F, and SnCl4∙5H2O are hydrolyzed into H+, F+, and Sn4+ ions. The formation of a small amount of HF formed from H+ and F+ ions can corrode the Si atom of the zeolite sheets and generate hydroxy-nest defect sites, Sn4+ ions fill up the hydroxy-nests to form isolated framework Sn active sites. The structure and active sites of the obtained materials are studied by various characterization methods. IEZ-Sn-PLS-3(S4R) possesses a 14 × 12-ring (R) pore system and framework Sn active sites. With enlarged pore sizes, IEZ-Sn-PLS-3(S4R) has been proved to be efficient for catalyzing the Baeyer–Villiger oxidation of 2-admantanone using H2O2 as the oxidant. The low Si/Sn sample resulted in a higher conversion compared to typical 12-ring zeolite Sn-Beta hydrothermally synthesized in an F− system.

An interlayer expanded zeolite, IEZ-PLS-3(Si–O–Si), was post-synthesized by the simple interlayer silylation of layered ECNU-9(P), which was derived from a lamellar precursor (PLS-3) using dichlorotetramethyldisiloxane (DCTMS) as the silylation reagent. The IEZ-PLS-3(Si–O–Si) was composed of ferrierite sheets and an intersected 14 × 12-ring (R) extra-large pore system. The results revealed that the IEZ-PLS-3(Si–O–Si) was composed of nanosized crystals, indicating that it is favorable for catalysis. Ti active sites were introduced into the framework of the IEZ-PLS-3(Si–O–Si) by solid-phase stirring in H2TiF6 aqueous solution at room temperature. The catalytic properties of the resulting material (Ti-IEZ-PLS-3(Si–O–Si)) were tested by carrying out the epoxidation of propene and allyl chloride, both of which have industrial application value. The Ti-IEZ-PLS-3(Si–O–Si) showed a higher catalytic activity compared to the typical well-known titanosilicate zeolites, including titanium silicalite-1 (TS-1) and Ti-MWW, which are currently used in industries. We also conducted the epoxidation of cyclohexene using bulk tert-butyl peroxide (TBHP) in decane as the oxidant to explore the pore properties of the Ti-IEZ-PLS-3(Si–O–Si). The Ti-IEZ-PLS-3(Si–O–Si) exhibited better catalytic performance than the TS-1 and Ti-MWW for cyclohexene due to its larger pore aperture.

A Z-scheme MoS2/CuO photocatalyst is successfully developed using a hydrothermal and calcination method, which has excellent activity (96%) in the degradation of 2-mercaptobenzothiazole (MBT) under visible light irradiation.

A novel ferrierite type zeolite named as IEZ-Al-PLS-3(S4R) with pore sizes of 14 x 12-ring (R) was post synthesized by simply interlayer silylation of lamellar precursor Al-PLS-3 taking 1,3,5,7-tetramethylcyclosilone (TMCS) as silane. Its catalytic properties were tested by isomerization/disproportionation of m-xylene, alkylation/acylation of anisole with benzyl alcohol/acetic anhydride. The catalytic performance of IEZ-Al-PLS-3(S4R) was compared with Al-PLS-3 (10 x 8-R) and IEZ-Al-PLS-3(1Si) (12 x 10-R) which were prepared by calcination or silylation using dimethoxydimethylsilane (DEDMS) as silane of as made Al-PLS-3 respectively. Since these materials have the same laminates composition, the differences of catalytic performance can be considered as the result of different pore sizes. We also prepared conventional 10-R zeolite ZSM-5 and 12-R zeolite Beta for control experiments. IEZ-Al-PLS-3(S4R) showed even higher catalytic activities than Beta as a result of its enlarged 14-R pore size.

Ti-PLS-3, a kind of layered titanosilicates of FER topology was developed by hydrothermal synthesis with the help of using pure silica PLS-3 as seed. The Si/Ti ratio of this material can be adjusted in a wide range from 20 − ∞. The structure and active sites of Ti-PLS-3 were detected by various characterization. After mild acid treatment to eliminate the hexa-coordinated extra-framework Ti species, the resulting material turned out to be a more effective catalyst for epoxidation of 1-hexene with H2O2 than reported FER type Ti-containing material Ti-FER.

Based on reported PDCz (1), eight isomers (2–9) were designed by changing Br substituent positions at the carbazole group to investigate the structure-property relationship by quantum chemistry calculations. The calculated results indicate that an appropriate Br substituent position at the carbazole group is essential for enhancing the spin–orbit coupling (SOC) strength. Among 2–9, The (n = 1–5) values of 3 and 7 with Br substituent at 3, 6-position and 1, 3-position are close to those of 1. However, other compounds (2, 4–6, 8 and 9) have significant increase in SOC values between singlet and triplet excited states. Thus, simply changing the Br substituent position would result in significant SOC variation. The systematical investigation on Br substituent position at the carbazole group would provide valuable information for choosing better Br position in experimental synthesis.

The reaction between titanium alkoxides, [Ti(OR)4], and surface silanol groups is widely used to generate grafted oxo-hydroxo titanium species, whose size is difficult to control. Partial capping of the surface silanols in the presence of the masking pattern of self-repelling tetramethylammonium ions allows us to isolate surface silanol islets, on which isolated titanium ions and dimeric oxo titanium species can be generated up to 2 Ti/Si mol %. Above this loading, and up to ∼8 Ti/Si mol %, higher oligomers (trimers, hexamers, octamers, and so on) are formed, reaching the size obtained at much lower loadings (<1 Ti/Si mol %) on a nonmodified silica surface. The downsizing effect produced on our organically modified surface is monitored from the blue-shift of the charge-transfer band of the Ti(IV) ions, measured by reflectance UV-visible spectroscopy. It is also mirrored by a higher catalytic activity in cyclohexene epoxidation, revealing that it is not only the isolated Ti species that are active but also the oligomers. Regarding the latter, the smaller they are, the more active they are.

Highly crystalline and (hydro)thermally stable zeolites with extra-large pores [≥14-ring (14-R)] are desirable as catalysts. A novel zeolite, ECNU-9, with an intersecting 14*12-R channel system was rationally designed and synthesized by a building block strategy, in which the interlayer expansion of a two-dimensional silicate structure was realized by combining organic amine assisted layer-stacking reorganization and subsequent silylation with a square-shaped single 4-ring (S4R) silane, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCS). The PLS-3 precursor was disassembled into building blocks and then intercalated with flexible and removable organic amine pillars to offer enough interlayer spacing for accommodating TMCS molecules. The additionally introduced building blocks interconnected the neighboring layers to construct new 14-R and 12-R pores. ECNU-9 possesses a well-ordered structure with a novel topology. The corresponding Ti-ECNU-9, with tetrahedral Ti ions in the framework, showed superior catalytic performance in the selective epoxidation of bulky alkenes.

A large‐pore ECNU‐19 material with unique pore system consisting of 12‐ring (12R) pore channels intersected by 8R channels was post‐synthesized via interlayer‐expansion of HUS‐2 lamellar silicate with silylating agent of 1,3‐dimethyltetramethoxydisiloxane (DMTMDS). In consideration of the fact that the HUS‐2 precursor possessed a special structure with a malposition of the neighboring layers as well as silicon vacancies on layer surface, a “detemplating disassembly – intercalation reassembly – silylation” strategy was proposed to realize a successful interlayer‐expansion and structural amending. An acid treatment was firstly performed to remove a part of the structure‐directing agent molecules, which favored the following intercalation by bulk organic species. The intercalation not only rearranged the relative position of up‐down layers but also provided enough interlayer space for the insertion of dimeric silane molecules. Two –OH groups attached to one silicon atom of the silane molecule reacted with two close silanols on the up‐surface layer, while the other two –OH groups condensed with two silanols on the down‐surface layer, which then connected the two layers via ‐Si‐O‐Si‐ pillars and constructed new 12R pores along a axis and 8R pores along c axis, respectively.