Photocatalytic dry reforming of methane (PDRM) provides a green approach for the co-conversion of greenhouse gases (GHGs), including CO2 and CH4, but the current design of bimetallic catalysts commits to light capture and carrier utilization, ignoring the decisive role of the surface electronic microenvironment on reaction kinetics, resulting in low syngas yields. This study focuses on the regulation of the electronic microenvironment on the catalyst surface, utilizing the significant difference in work function (WF) between Pt and Ru to design the Pt1Ru5/ZnO bimetallic catalyst. The directional migration of electrons can form electron-rich Pt sites and electron-deficient Ru sites, creating an asymmetric electronic microenvironment that enhances the activation of CO2 and the dissociation of CH4, respectively. The CO and H2 formation rates of the optimized catalyst Pt1Ru5/ ZnO are 228.5 mu mol center dot g- 1 center dot h- 1 and 54.5 mu mol center dot g- 1 center dot h- 1, respectively. The CO/H2 ratio is reduced from 46.5 to 4.2, indicating that the side reaction is inhibited to a certain extent. DFT calculations and experimental characterizations reveal the construction of asymmetric dual active sites and reaction mechanisms. This study elucidates the synergistic mechanism of PtRu dual-active sites in promoting CO2 dissociation and CH4 dehydrogenation through electronic structure regulation. The process highlights the PtRu synergy, optimizes carrier kinetics, and facilitates dual transformation pathways, thereby providing a novel strategy for the design of highly efficient PDRM catalysts.

The hydrolysis of carbonyl sulfide (COS) to hydrogen sulfide (H2S) is of paramount importance in blast furnace gas (BFG) purification. In practical applications, the H2S/COS ratio fluctuates due to variations in ironmaking raw materials and operational conditions, while the inevitable presence of oxygen (O2) leads to catalyst deactivation, severely compromising the hydrolysis process. In this study, K-modified NaY zeolite catalysts were prepared via impregnation, and the effects of temperature, H2S/COS ratio, and O2 concentration on COS hydrolysis performance were systematically investigated. Experimental results demonstrate that the NaY zeolite loaded with 10% KOH exhibits good adaptability to fluctuations in the H2S/COS ratio and possesses excellent oxygen resistance. Optimal catalytic performance was achieved at 100 degrees C with an H2S:COS ratio of 1:3 and an O2 concentration of 0.3%, under which the COS hydrolysis efficiency exceeded 92% for 12 hours. Characterization results indicate that weak and medium-strength basic sites synergistically regulate adsorption/desorption behaviors and the local acid-base microenvironment. This synergy prevents issues such as insufficient reactant adsorption or hindered product desorption caused by the dominance of a single type of basic site, thereby significantly optimizing the COS hydrolysis performance. This study proposes an effective solution for COS hydrolysis and provides fundamental data for further catalyst optimization and industrial application.

Propane is a typical volatile organic compound (VOC) in coal chemical processing and petroleum refining. However, coexisting SO2 significantly impairs its catalytic oxidative removal, potentially causing catalyst poisoning and deactivation. This study systematically elucidated the inhibitory effects of SO2 on the catalytic oxidation of propane over the Ru@CoMn2O4 catalyst system. Under continuous exposure to 30 ppm SO2, propane conversion plummeted by 30% within two hours. Mechanistic studies revealed that SO2 selectively bound to high-valent Mn sites rather than preferentially interacting with Co sites, leading to the formation of MnSO4 particles. These particles were directly corroborated by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses. After four hours of exposure to SO2, roughly 11.8 mole percent of manganese in the catalyst was converted into MnSO4. These deposits physically blocked active sites, reduced specific surface area, and disrupted redox cycling. As a result, their combined effects diminished performance progressively, ultimately leading to complete deactivation. Furthermore, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) confirmed that SO2 suppressed C=C bond oxidation in propane intermediates, thereby directly limiting conversion efficiency. Combining qualitative and quantitative methods, we characterized SO2-induced poisoning during propane oxidation. This work provides guidelines and strategies for designing anti-sulfur catalysts at the elemental scale for the catalytic combustion of low-carbon alkanes.

The stability of Al2O3-based catalysts used to hydrolyze COS from blast furnace gas is significantly challenging in the iron and steel industry. Targeting this challenge, the enhanced catalytic activity and stability are demonstrated, using Sm and K dual-metal co-modified 3-4 mm Al2O3 pellets commonly used in industry. In a simulated blast furnace gas atmosphere, the catalyst impregnated with K followed by Sm and calcined twice(Sm-*K/Al2O3) show the highest hydrolysis efficiency, reaching 98 % during 10 h. XPS combined with CO2-TPD and EPR shows that there is a strong electron transfer between Sm and K, which significantly increases the quantity of weak basic sites and oxygen vacancies. With the introduction of Sm, more stable lattice oxygen is generated, which further prevents the sulfation of K and maintains good stability. In addition, the COS hydrolysis reaction mechanism of Sm-*K/Al2O3 has been proposed by in-situ DRIFTS. This work provides convenience for further research on catalysts promoting COS hydrolysis and their industrial applications.

Photoelectrocatalytic coupling CO2 and volatile organic compounds (VOCs) is a promising green strategy for the synergistic conversion of the two carbon-containing resources to C-2 products. The catalytic efficiency is always at the mercy of chemical inertness of CO2 and the competitive hydrogen evolution of H2O. Herein, a modified g-C3N4/ZnAl-LDH Z-scheme heterojunction catalyst with dual reaction site was rationally designed and precisely constructed. The Faraday efficiency of ethanol reached 68.67% with a corresponding formation rate of 227.3 mu mol g(-1) h(-1). As revealed by in-situ characterizations and density functional theory calculations, CO2 and HCHO were absorbed at Zn site and N site, respectively. Then, *CO generated from CO2 and HCHO was converted to *CH3O and *CHO on the dual-active-site heterojunction. The detailed reaction mechanism experiments indicated that C-C coupling only occurred between *CO and *CH3O in electrocatalysis process. Apart from the "*CO + *CH3O" path, another "*CO + *CHO" coupling path was also detected in photoelectrocatalytic process. The selectivity of ethanol was significantly enhanced due to the synthesis of dual-site catalyst and the dual-path coupling path between CO2 and HCHO simultaneously driven by light and electricity.

Noble metals have become a research hotspot for the oxidation of light alkanes due to their low ignition temperature and easy activation of C-H; however, sintering and a high price limit their industrial applications. The preparation of effective and low-noble-metal catalysts still presents profound challenges. Herein, we describe how a Ru@CoMn2O4 spinel catalyst was synthesized via Ru in situ doping to promote the activity of propane oxidation. Ru@CoMn2O4 exhibited much higher catalytic activity than CoMn2O4, achieving 90% propane conversion at 217 °C. H2-TPR, O2-TPD, and XPS were used to evaluate the catalyst adsorption/lattice oxygen activity and the adsorption and catalytic oxidation capacity of propane. It could be concluded that Ru promoted synergistic interactions between cobalt and manganese, leading to electron transfer from the highly electronegative Ru to Co2+ and Mn3+. Compared with CoMn2O4, 0.1% Ru@CoMn2O4, with a higher quantity of lattice oxygen and oxygen mobility, possessed a stronger capability of reducibility, which was the main reason for the significant increase in the activity of Ru@CoMn2O4. In addition, intermediates of the reaction between adsorbed propane and lattice oxygen on the catalyst were monitored by in situ DRIFTS. This work highlights a new strategy for the design of a low-noble-metal catalyst for the efficient oxidation of propane.

Nitrogen oxides (NOx) and volatile organic compounds (VOCs) are the main pollutants in flue gas, and the synergistic removal of NOx and VOCs in the presence of SO2 is still a challenge. In this work, the microstructure of NiMn2O4-CeO2 catalysts and the distribution of sulfur-containing substances were studied to reveal the inactivation mechanism of sulfur poisoning. NOx conversion could reach more than 80 % at 100-250 degrees C, and C3H8 conversion could achieve 90 % at 210 degrees C in the synergistic reaction on NiMn2O4-CeO2 catalyst, which has dual active sites with propane oxidation and SCR reactions carried out at Mn and Ni sites, respectively. In addition, the intrinsic effect of SO2 on propane oxidation and NOx reduction were investigated by decoupling. For propane oxidation, mechanistic studies have shown that manganese sulfate generated by SO2 hindered further reactions by inhibiting the breaking of the C--C bond. For denitration reaction, the generation of sulfate not only resulted in electron transfer from Ni to Mn thereby reducing reaction activity, but also blocked the L-H pathway by inhibiting NO adsorption. This work provides guidelines and strategies to mitigate SO2 poisoning in the simultaneous removal of NOx and light alkane.

Light alkane VOCs are currently the most difficult VOCs to deal with in the petroleum and coal chemical in-dustries due to their short carbon chains and stable molecular structures. On account of the metal components of spinel are diverse and the structure can be adjusted. Thus, a series of A-site cations substituted AMn2Ox (A = Co, Cu, Ni, Zn, Ce) spinel catalysts were prepared and the impacts of A-site cations on the oxidation of alkane were revealed. It was found that A-site metal ions made a big difference in the low-temperature reduction, lattice oxygen activity, high-valent manganese ion content, and oxygen vacancies with NiMn2O4 had the highest cat-alytic activity with a conversion of 90 % at 232 degrees C. In addition, in-situ DRIFTs were performed to investigate the underlying oxidation mechanisms for propane oxidation. We found that propane is firstly dehydrogenated by adsorption on the active site and then oxidized to carboxylates and carbonates, which are further converted to CO2 and H2O. Moreover, the catalyst also showed good stability and robust resistance of H2O and SO2. The excellent activity exhibited by Ni-Mn-based spinels may shed light on the development of efficient catalysts for light alkanes catalytic oxidation.

Under the guidance of the idea of “treating waste with waste”, copper-loaded carbon-based catalysts were prepared in situ using waste chelating resin with adsorbed copper. The effect of the catalyst activation temperature on dye brilliant red (X-3B) degradation was investigated and the characterization of the catalysts was analyzed. The results show that a catalyst activated at 800 °C (Cu-AC-800) has the largest specific surface area and abundant pore structure and the highest proportion of Cu under low valence states, which leads to the best performance in adsorbing and degrading X-3B. The influences of operation conditions and inorganic salt anions on persulfate (PS) activation were also investigated. Moreover, the degradation mechanism was preliminarily explored by quenching reactions. The main active free radicals in the system were determined as sulfate radicals (•SO4−). Given its use in solid waste recycling, copper-loaded carbon-based catalyst may provide some new insights for the remediation of wastewater.

In this work, the activation effect of vacuum thermal treatment on MIL-101(Fe) (MIL: Materials of Institute Lavoisier) was investigated for the first time. It demonstrated that vacuum thermal activation could accelerate the activation of persulfate (PS) by MIL-101(Fe), and the enhancement of the catalytic capacity of MIL-101(Fe) was mainly attributed to the change in the FeII/FeIII mixed-valence center. The results of the SEM and XRD showed that vacuum thermal activation had a negligible effect on the crystal structure and particle morphology of MIL-101(Fe). Meanwhile, the higher temperature of vacuum thermal activation caused a higher relative content ratio of FeII/FeIII. A widely used azo dye, X-3B, was chosen as the probe molecule to investigate the catalytic performance of all samples. The results showed that the activated samples could remove X-3B more effectively, and the sample activated at 150 °C without regeneration could effectively activate PS to remove X-3B for at least 5 runs and approximately 900 min. This work highlights the often-overlooked activation effect of vacuum thermal treatment and provides a simple way to improve the catalytic capacity and reusability of MIL-101(Fe) which is beneficial for the application of MIL-101(Fe)/PS systems in azo dye wastewater treatment.

In recent years, sulfate radical-based advanced oxidation has received increasing attention for the treatment of water and wastewater. However, the chemical oxygen demand (COD), a common measure of gross organic contamination, is subject to interference from residual persulfate in the treated water. In this study, a new method, based on addition of sodium sulfite (Na2SO3) and heating, has been developed to eliminate the interference of remaining potassium persulfate (PSk) on COD analysis. Results of batch experiments show that potassium persulfate can be efficiently removed with molar ratio of Na2SO3/potassium persulfate ≥ 2 and heating at 90 °C for 60 min. This method (Na2SO3–heating treatment) was further tested in a phenol wastewater and a coal industry wastewater. The deviation of COD values of Na2SO3–heating treatment was lower than  5%, which was much lower than the deviation of the calibration curve method, of more than 14%. This new method could be applied to water samples containing persulfate and organic substances and help researchers to accurately evaluate performance of sulfate radical-based advanced oxidation processes.

Iron titanium catalysts with uniform mesopores were synthesized using cetyl trimethyl ammonium bromide (CTAB) as a template-directing agent, and applied to the selective catalytic reduction of NO with NH3. It was found that the catalyst exhibited high catalytic activity in a wide range of operating temperatures and good stability. The samples were characterized by means of N-2-physisorption, XRD, TEM, TPD, XPS and in situ DRIFTS technologies. Results showed that CTAB acted as both a "structural" and "chemical" promoter, which not only increased the specific surface area of the catalysts by optimizing the pore size, but also promoted the formation of a crystalline structure rather than an amorphous one, thereby leading to increased catalytic activity. Moreover, in situ DRIFTS revealed that Lewis acids played key roles in the SCR reaction, and the enhanced adsorption of bridged nitrate and coordinated NH3 on Lewis acids was an important reason for the excellent catalytic performance.

•CT-FeTi catalysts showed high SCR activity and good H2O resistance.•CTAB optimized the pore size to avoid being excessively enlarged in the presence of H2O.•CTAB promoted the adsorption of bridging nitrate and NH3 species on Lewis acid sites.

Sulfur doped activated carbon with strong adsorption ability and excellent catalytic activity is successfully synthesized through a one-pot process.

V2O5/AC catalyst has widely been researched with its highly active for SO2 removal in our group. In this process, previous research considered that the final desulfurization product of V2O5/AC is H2SO4, which is captured by storing in the pores of AC, and regeneration of the SO2-captured materials is necessary to recover its ability to SO2 adsorption. In this paper, CO is firstly chosen as a regeneration gas to catalytic reduce desorption H2SO4 on V2O5/AC. Compared with thermal regeneration, CO regeneration can recover the activity and stability of V2O5/AC better. The best regeneration condition is 0.15% CO/N-2 at 350 degrees C with 90 min. A part of sulfur adsorbed on V2O5/AC cannot be desorbed even in CO regeneration. A mechanism is proposed in which CO regeneration promotes H2SO4 desorption and decreases the consumption of AC. Thus the desulfurization activity and stability is recovered or kept better than thermal regeneration. The activity of sulfur recovery is correlated to temperature and the feed CO/SO2 molar ratios. (C) 2017 Elsevier B.V. All rights reserved.

Sulfate radicals (SO4 center dot(-)) generated from persulfate (PS) activated by carbocatalysis is expected to provide an environmentally friendly and highly efficient catalytic oxidation process for aqueous organics degradation. Herein, a novel sulfur-doped hierarchically porous carbon with both structural and compositional modification was proposed for PS activation by using thiophene as sulfur/carbon precursor and KOH as activator. The effect of annealing temperature on its textural properties and surface chemistry was characterized by Elemental analysis, N-2 sorption isotherms, X-ray photoelectron spectroscopy, Fourier transform infrared spectra, Raman spectra and X-ray diffraction. The as-prepared sample treated at 800 degrees C (SDAC-800) demonstrated outstanding catalytic activity for activation of PS to degrade 4-chlorophenol (4CP). Studies on the role of sulfur in the catalytic activity enhancement were carried out by comparing with a sulfur-free activated carbon and a carbon model (reduced graphene oxide (rGO)). The effects of catalyst dosage, initial 4CP concentration, and reaction temperature on 4CP degradation were comprehensively investigated. In addition, contrast tests with other conventional PS activation methods, SDAC-800 reusability and its general applicability tests were also carried out. The mechanism of PS activation and 4CP oxidation was elucidated by using quenching tests with chloridion, L-histidine and ethanol as radical scavengers. It revealed that the conventional radical pathway was not a critical role in 4CP degradation. In contrast, the process was controlled by both particle-surface interaction and non-radical pathway, and the latter played a dominant role.

In-situ S-doped activated carbons with huge specific surface areas and developed total pore volumes were prepared by chemical activation of polythiophene with KOH as activator under different annealing temperatures (from 600 to 800 degrees C). The obtained material treated at 800 degrees C (ACS-800) showed the best catalytic activity for 4-chlorophenol (4CP) oxidation. Almost 100% 4CP removal was attained for ACS-800 in 60 min with an apparent rate constant of 0.083 min(-1), which was much higher than that of S-free activated carbon (0.032 min(-1)). N-2 sorption isotherms and XPS spectra indicated that the sulfur doping and the removal of acidic functional groups (such as sulphone groups and carboxyl groups) at high temperature strongly enhanced the catalytic activity of ACS-800. In comparison experiments, ACS-800 presented superior performance in PS activation to conventional catalysis techniques (Co3O4, Fe3O4, zero-valent iron (ZVI), reduced graphene oxide (rGO), and multi-walled carbon nanotube (MWCNT)). Moreover, different peroxides and various aqueous organics were used to further evaluate the catalytic activity of ACS-800. Results showed that ACS-800 could activate various peroxides and degrade different kinds of contaminants. The high catalytic activity and general applicability of ACS-800 make it to be a promising metal-free catalyst for environmental remediation.

An Fe/TiO2 catalyst with uniform mesopores was synthesized using Pluronic F127 as a structure-directing agent. This catalyst was used for selective catalytic reduction of NO with NH3. The catalytic activity and resistance to H2O and SO2 of Fe/TiO2 prepared by a template method were better than those of catalysts synthesized using impregnation and coprecipitation. The samples were characterized using N2-physisorption, transmission electron microscopy, ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared Fourier-transform spectroscopy. The results showed that Pluronic F127 acted as a structural and chemical promoter; it not only promoted the formation of a uniform mesoporous structure, leading to a higher surface area, but also improved dispersion of the active phase. In addition, the larger number of Lewis acidic sites, indicated by the presence of coordinated NH3 species (1188 cm−1) and the N–H stretching modes of coordinated NH3 (3242 and 3388 cm−1), were beneficial to mid-temperature selective catalytic reduction reactions.

The primary reaction kinetics of the isolated photosystem II particles and photosystem II core complexes from spinach (Spinacia deracea Mill.) was investigated using the time-resolved fluorescence spectroscopy with 470 fs time resolution. 2 to 4 lifetime components were detected by the multi-exponential curve fitting method. These components were analyzed and discussed in terms of different kinetic processes. It is suggested that 3 ps component is attributed to the charge separation and 0.8 ps, 12 ps, 25 ps and 100 ps components are related to the energy transfer processes. A possible kinetic scheme in photosystem II reaction center was proposed based upon the reported previously result.

In the present study we investigated the kinetics of the initial charge separation and energy transfer in the PS II reaction center using pico-second and femto-second time-resolved techniques. We conclude that there are energy transfer processes between ß-Car or Pheo and P680 in the PSII reaction center. The time constant of energy transfer from Pheo to P680 is less than 100 ps, while that from (ß-Car to P680 is about 350 ps. For the initial charge separation in the PS II reaction center, the preliminary finding supported the about 3-ps time constant of charge separation. The possible kinetic scheme in PS II reaction center was proposed. Further experiments are in progress.