Semiconductor Photocatalysts for Non-oxidative Coupling, Dry Reforming and Steam Reforming of Methane

Abstract

Methane is one of the promising alternatives of petroleum, which should be used for not only a fuel but also a resource for hydrogen and more useful chemicals as with the petroleum. However, the selective methane conversion to them is still difficult in contrast to the combustion. Three types of photocatalytic reactions for methane conversion, i.e., the photocatalytic non-oxidative coupling of methane (2CH4 → C2H6 + H2), the photocatalytic dry reforming of methane (CH4 + CO2 → 2CO + 2H2) and the photocatalytic steam reforming of methane (CH4 + 2H2O → 4H2 + CO2), can take place around room temperature or at a mild condition such as 473 K using photoenergy and semiconductor photocatalyst. In the present short review, the details of each photocatalytic reaction and the design concept of the semiconductor photocatalysts for each photocatalytic methane conversion were summarized and discussed.