Thermo–Photo Catalysis for Methanol Synthesis from Syngas

It is well-known that the synthesis of methanol from syngas is based on thermal catalysis (TC). However, in this work, light was introduced into the thermal catalytic process, creating a novel thermo–photo catalysis (TPC) for methanol production from syngas over a Cu/Zn/Al catalyst. It was demonstrated that the yield of methanol from the TPC process was 2.8 times that from the TC process at a catalyst temperature of 350 °C. Unlike the general recognition that the catalytic performance is mainly dependent on the temperature of the catalyst surface, TPC is also greatly influenced by the reactant temperature. The yield of methanol was enhanced 3.3 times by increasing the reactant temperature from 93 to 260 °C at a constant catalyst-surface temperature of 350 °C. Furthermore, although Cu+ is the active site for thermal catalysis, Cu++ plays an important role in thermo–photo catalysis. This work provides insights into the synergistic effect of thermal energy and photoenergy in thermo–photo catalytic syngas conversion.