The structure and catalytic desulfurization characteristics of CeO2-TiO2 mixed oxides were investigated by means ofX-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and catalytic activity tests. Acco...The structure and catalytic desulfurization characteristics of CeO2-TiO2 mixed oxides were investigated by means ofX-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and catalytic activity tests. According to the results, a CeO2-TiO2solid solution is formed when the mole ratio of cerium to titanium n（Ce）：n（Ti） is 5：5 or greater, and the most suitable n（Ce）：n（Ti） isdetermined as 7：3, over which the conversion rate of SO2 and the yield of sulfur at 500℃ reach 93% and 99%, respectively.According to the activity testing curve, Ce0.7Ti0.3O2 （n（Ce）：n（Ti）=7：3） without any pretreatment can be gradually activated by reagentgas after about 10 min, and reaches a steady activation status 60 min later. The XPS results of Ce0.7Ti0.3O2 after different time ofSO2＋CO reaction show that CeO2 is the active component that offers the redox couple Ce4＋/Ce3＋ and the labile oxygen vacancies, andTiO2 only functions as a catalyst structure stabilizer during the catalytic reaction process. After 48 h of catalytic reaction at 500℃,Ce0.7Ti0.3O2 still maintains a stable structure without being vulcanized, demonstrating its good anti-sulfur poisoning performance.展开更多
Single-atom catalysts(SACs)have attracted increasing concerns in electrocatalysis because of their maximal metal atom utilization,distinctive electronic properties,and catalytic performance.However,the isolated single...Single-atom catalysts(SACs)have attracted increasing concerns in electrocatalysis because of their maximal metal atom utilization,distinctive electronic properties,and catalytic performance.However,the isolated single sites are disadvantageous for reactions that require simultaneously activating different reactants/intermediates.Fully exposed metal cluster catalyst(FECC),inheriting the merits of SACs and metallic nanoparticles,can synergistically adsorb and activate reactants/intermediates on their multi-atomic sites,demonstrating great promise in electrocatalytic reactions.Here a facile method to regulate the atomic dispersion of Ni species from cluster to single-atom scale for efficient CO_(2) reduction was developed.The obtained Ni FECC exhibits high Faradaic efficiency of CO up to 99%,high CO partial current density of 347.2 mA cm^(−2),and robust durability under 20 h electrolysis.Theoretical calculations illuminate that the ensemble of multiple Ni atoms regulated by sulfur atoms accelerates the reaction kinetics and thus improves CO production.展开更多
文摘The structure and catalytic desulfurization characteristics of CeO2-TiO2 mixed oxides were investigated by means ofX-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and catalytic activity tests. According to the results, a CeO2-TiO2solid solution is formed when the mole ratio of cerium to titanium n（Ce）：n（Ti） is 5：5 or greater, and the most suitable n（Ce）：n（Ti） isdetermined as 7：3, over which the conversion rate of SO2 and the yield of sulfur at 500℃ reach 93% and 99%, respectively.According to the activity testing curve, Ce0.7Ti0.3O2 （n（Ce）：n（Ti）=7：3） without any pretreatment can be gradually activated by reagentgas after about 10 min, and reaches a steady activation status 60 min later. The XPS results of Ce0.7Ti0.3O2 after different time ofSO2＋CO reaction show that CeO2 is the active component that offers the redox couple Ce4＋/Ce3＋ and the labile oxygen vacancies, andTiO2 only functions as a catalyst structure stabilizer during the catalytic reaction process. After 48 h of catalytic reaction at 500℃,Ce0.7Ti0.3O2 still maintains a stable structure without being vulcanized, demonstrating its good anti-sulfur poisoning performance.
基金funding from the Alexander von Humboldt Foundation(Germany)supported by the National Key R&D Program of China(2020YFB1505603)+2 种基金the National Natural Science Foundation of China(51925102)Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3)Youth Innovation Promotion Association CAS(E1202002)。
文摘Single-atom catalysts(SACs)have attracted increasing concerns in electrocatalysis because of their maximal metal atom utilization,distinctive electronic properties,and catalytic performance.However,the isolated single sites are disadvantageous for reactions that require simultaneously activating different reactants/intermediates.Fully exposed metal cluster catalyst(FECC),inheriting the merits of SACs and metallic nanoparticles,can synergistically adsorb and activate reactants/intermediates on their multi-atomic sites,demonstrating great promise in electrocatalytic reactions.Here a facile method to regulate the atomic dispersion of Ni species from cluster to single-atom scale for efficient CO_(2) reduction was developed.The obtained Ni FECC exhibits high Faradaic efficiency of CO up to 99%,high CO partial current density of 347.2 mA cm^(−2),and robust durability under 20 h electrolysis.Theoretical calculations illuminate that the ensemble of multiple Ni atoms regulated by sulfur atoms accelerates the reaction kinetics and thus improves CO production.
