On-demand continuous H2 release by methanol dehydrogenation and reforming via photocatalysis in a membrane reactor

Abstract

Photocatalytic methanol dehydrogenation and reforming is viewed as a promising strategy to realize H₂ production on demand. Herein, we report highly dispersed Cu_xO nanoparticles on TiO₂ (PC50) for continuous H₂ production from aqueous methanol solution by photocatalysis in a flow reactor at a low temperature and under atmospheric pressure. The flow membrane reactor improves the H₂ production rate by a factor of 1.63 compared with the widely used batch reactor thanks to enhanced mass transfer. Furthermore, the optimized 1% Cu/PC50 exhibits a 17-times higher H₂ yield (33 702 μmol g⁻¹ h⁻¹) than pristine PC50. The apparent activation energy on 1% Cu/PC50 is found to be halved to as low as 4.0 kJ mol⁻¹, which is much less than those in other methanol reforming processes. The diverse characterisation proposes that Cu_xO as electron acceptors could effectively promote charge separation and work as active sites for the reduction reaction, together with the improved mass transfer in the reactor leading to enhanced photocatalytic performance.