Novel layered triple hydroxide sphere CO2 adsorbent supported copper nanocluster catalyst for efficient methanol synthesis via CO2 hydrogenation

Abstract

Copper-based catalysts are playing important roles in CO2 hydrogenation to methanol. Active copper provides sites for H2 dissociation, whereas CO2 adsorption and activation cannot be ignored either. Accordingly, novel Cu/LTH catalysts with copper nanoclusters supported on layered triple hydroxide (LTH) sphere CO2 adsorbent were developed to improve microstructures and CO2 adsorption capabilities simultaneously. The results show increasements in copper content enlarge crystallite sizes yet reduce surface areas and pore volumes. All Cu/LTH catalysts consist of uniformly dispersed copper nanoclusters on external surfaces of LTH. Catalytic tests reveal remarkable properties of Cu/LTH catalysts compared with conventional catalysts. Further mechanism analyses demonstrate LTH can boost CO2 adsorption capability at reaction conditions. Due to metal-support interactions, copper species in Cu3/LTH are more easily reduced mainly in the form of Cu+, benefiting directional CO2 conversion to methanol. Thus, it is feasible and efficient to ameliorate catalyst by incorporating adsorbent for enhanced CO2 adsorption process.