In this study,two Ru/TiO_(2)samples with different TiO_(2)facets were prepared to investigate their photo-thermal catalytic CO_(2)+H_(2)reaction behavior.Without UV irradiation,the Ru/TiO_(2)with 67%{001}facet(3 RT)di...In this study,two Ru/TiO_(2)samples with different TiO_(2)facets were prepared to investigate their photo-thermal catalytic CO_(2)+H_(2)reaction behavior.Without UV irradiation,the Ru/TiO_(2)with 67%{001}facet(3 RT)displayed improved thermal catalytic activity for CO_(2)methanation than that of Ru/TiO_(2)with 30%{001}facet(0 RT).After H_(2)pretreatment,both samples exhibited enhanced thermal catalytic activities,but the H_(2)-treated 3 RT(3 RT-H)exhibited superior activity to that of the H_(2)-treated 0 RT(0 RT-H).Under UV irradiation,3 RT-H exhibited apparent photo-promoted thermal catalytic activity and stability,but the enhanced catalytic activity was lower than that of 0 RT-H.Based on the characterization results,it is proposed that both the surface oxygen vacancies(Vos)(activating CO_(2))and the metallic Ru nanoparticles(activating H_(2))were mainly responsible for CO_(2)methanation.For 0 RT,H_(2)pretreatment and subsequent UV irradiation did not promote the formation of Vos,resulting in low catalytic activity.For 3 RT,on the one hand,H_(2)pretreatment promoted the formation of Vos,which were regenerated under UV irradiation;on the other hand,the photogenerated electrons from TiO_(2)transferred to Ru to maintain the metallic Ru nanoparticles.Both behaviors promoted the activation of CO_(2)and H_(2)and enhanced CO_(2)methanation.Moreover,the photogenerated holes favored the dissociated H at Ru migrating to TiO_(2),also promoting CO_(2)methanation.These behaviors occurring on 3 RT-H may be attributed to the suitable metal-support interaction between the Ru nanoparticles and TiO_(2){001},resulting in the easy activation of lattice oxygen in TiO_(2)to Vos.With reference to the analysis of intermediates,a photo-thermal reaction mechanism is proposed for the Ru/TiO_(2){001}facet sample.展开更多
文摘In this study,two Ru/TiO_(2)samples with different TiO_(2)facets were prepared to investigate their photo-thermal catalytic CO_(2)+H_(2)reaction behavior.Without UV irradiation,the Ru/TiO_(2)with 67%{001}facet(3 RT)displayed improved thermal catalytic activity for CO_(2)methanation than that of Ru/TiO_(2)with 30%{001}facet(0 RT).After H_(2)pretreatment,both samples exhibited enhanced thermal catalytic activities,but the H_(2)-treated 3 RT(3 RT-H)exhibited superior activity to that of the H_(2)-treated 0 RT(0 RT-H).Under UV irradiation,3 RT-H exhibited apparent photo-promoted thermal catalytic activity and stability,but the enhanced catalytic activity was lower than that of 0 RT-H.Based on the characterization results,it is proposed that both the surface oxygen vacancies(Vos)(activating CO_(2))and the metallic Ru nanoparticles(activating H_(2))were mainly responsible for CO_(2)methanation.For 0 RT,H_(2)pretreatment and subsequent UV irradiation did not promote the formation of Vos,resulting in low catalytic activity.For 3 RT,on the one hand,H_(2)pretreatment promoted the formation of Vos,which were regenerated under UV irradiation;on the other hand,the photogenerated electrons from TiO_(2)transferred to Ru to maintain the metallic Ru nanoparticles.Both behaviors promoted the activation of CO_(2)and H_(2)and enhanced CO_(2)methanation.Moreover,the photogenerated holes favored the dissociated H at Ru migrating to TiO_(2),also promoting CO_(2)methanation.These behaviors occurring on 3 RT-H may be attributed to the suitable metal-support interaction between the Ru nanoparticles and TiO_(2){001},resulting in the easy activation of lattice oxygen in TiO_(2)to Vos.With reference to the analysis of intermediates,a photo-thermal reaction mechanism is proposed for the Ru/TiO_(2){001}facet sample.
