Highly hydrophilic multi-channel CHA membrane for the fabrication of packed bed membrane reactor to boost CO2 hydrogenation to methanol

Abstract

The conversion of CO₂ into value-added chemicals has drawn intense interest in science and industry. In recent years, thermal catalysis based CO₂ hydrogenation to methanol has emerged as a prominent research area. However, conventional catalysts employed in thermocatalytic reactions exhibit inadequate performances in terms of CO₂ conversion, methanol selectivity, and long-term stability. To address these challenges, firstly, we have developed a metal–organic framework (MOF) Cu/Zn/Zr-BTC derivatived CuO-ZnO-ZrO₂ catalyst for CO₂ hydrogenation. Subsequently, the Cu/Zn/Zr-BTC derivatived CuO-ZnO-ZrO₂ catalyst was loaded into the inside of the 19-channel monolithic chabazite (CHA) zeolite membrane to fabricate a multi-channel packed-bed membrane reactor (MC-PBMR) for CO₂ hydrogenation to methanol. Attributing to in-situ removal of by-product water through the highly water-selective 19-channel CHA zeolite membrane during CO₂ hydrogenation to methanol, high CO₂ conversion (37.6 %) and methanol selectivity (93.4 %) can be obtained at 548 K and 3.0 MPa. The MC-PBMR demonstrates exceptional thermal stability and mechanical durability, showing no performance degradation after 200 h time-on-stream at 548 K and 3.0 MPa. Further, in comparison with the single tubular membrane reactor, the multi-channel CHA membrane reactor has a higher thermal stability and surface-to-volume ratio, enhanced mechanical strength, and superior packing density, enabled as a viable candidate for scalable, high-efficiency methanol production. This novel design is expected to effectively address the operational and industrial demands for sustainable CO₂ hydrogenation applications.