Synthesis of Cu–ZnO–Pt@HZSM-5 catalytic membrane reactor for CO₂ hydrogenation to dimethyl ether

CO₂ hydrogenation to dimethyl ether (DME) has drawn increasing interest in science and industry. However, the conversion of CO₂ to DME is challenging due to the limitation of thermodynamic equilibrium and the water-induced degradation of the catalysts in a catalytic fixed bed reactor (CFBR). In this study, a novel reaction-separation coupling Cu–ZnO–Pt@HZSM-5 catalytic membrane reactor (CMR) was fabricated for CO₂ hydrogenation to DME. Owing to continuous separation of the by-product steam by using an HZSM-5 membrane, the limitation of thermodynamic equilibrium can be broken effectively, thus leading to a substantially enhanced CO₂ conversion (from 24.9% in the CFBR to 41.1% in the CMR) and DME selectivity (from 53.7% in the CFBR to 100% in the CMR). Further, water-induced degradation of the catalyst can be restrained because of water removal, thus keeping a high catalytic activity for a long time.