Photoassisted Selective Steam and Dry Reforming of Methane to Syngas Catalyzed by Rhodium-Vanadium Bimetallic Oxide Cluster Anions at Room Temperature

摘要

Photoassisted steam reforming and dry (CO2) reforming of methane (SRM and DRM) at room temperature with high syngas selectivity have been achieved in the gas-phase catalysis for the first time. The catalysts used are bimetallic rhodium-vanadium oxide cluster anions of Rh2VO1-3-. Both the oxidation of methane and reduction of H2O/CO(2)can take place efficiently in the dark while the pivotal step to govern syngas selectivity is photo-excitation of the reaction intermediates Rh(2)VO(2,3)CH(2)(-)to specific electronically excited states that can selectively produce CO and H-2. Electronic excitation over Rh(2)VO(2,3)CH(2)(-)to control the syngas selectivity is further confirmed from the comparison with the thermal excitation of Rh2VO2,3CH2-, which leads to diversity of products. The atomic-level mechanism obtained from the well-controlled cluster reactions provides insight into the process of selective syngas production from the photocatalytic SRM and DRM reactions over supported metal oxide catalysts.