2020/07/06 by Xiaoliang Liu, Mengheng Wang, Haoren Yin +5 · 3 citations
Chemical Engineering · Materials Science · #Catalysis and Oxidation Reactions #Catalysts for Methane Reforming #Catalytic Processes in Materials Science
paper · doi:10.1021/acscatal.0c01579
openalex publication_date 2020/07/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Transformation of syngas (H 2 /CO) and hydrogenation of CO 2 into lower olefins are attractive routes for chemical utilization of various carbon resources and CO 2, but both suffer from limited product selectivity. Tandem catalysis that integrates the activation of CO or CO 2 to an intermediate and the subsequent controllable C–C bond formation to form lower olefins offers a promising approach. Here, we report the hydrogenation of both CO and CO 2 over bifunctional catalysts composed of a spinel binary metal oxide and SAPO-34. ZnAl 2 O 4 /SAPO-34 and ZnGa 2 O 4 /SAPO-34 are found to be highly selective for the synthesis of lower olefins from both CO and CO 2 . Our studies reveal that the oxygen vacancy site on metal oxides plays a pivotal role in the adsorption and activation of CO or CO 2, while the −Zn–O– domain accounts for H 2 activation. We demonstrate that methanol and dimethyl ether formed on metal oxide are the reaction intermediates, which are subsequently converted to lower olefins by the Brønsted acid sites in zeolite. The hydrogenation of CO and CO 2 on metal oxide surfaces proceeds via the same formate and methoxide species. We elucidate that the water–gas shift reaction on oxide surfaces is responsible for CO 2 formation during syngas conversion. The cofeeding of CO 2 in syngas offers a useful strategy to inhibit CO 2 formation.