Non-syngas direct steam reforming of methanol to hydrogen and carbon dioxide at low temperature

Abstract

A non-syngas direct steam reforming route is investigated for the conversion of methanol to hydrogen and carbon dioxide over a CuZnGaO_x catalyst at 150–200 °C. This route is in marked contrast with the conventional complex route involving steam reformation to syngas (CO/H₂) at high temperature, followed by water gas shift and CO cleanup stages for hydrogen production. Here we report that high quality hydrogen and carbon dioxide can be produced in a single-step reaction over the catalyst, with no detectable CO (below detection limit of 1 ppm). This can be used to supply proton exchange membrane fuel cells for mobile applications without invoking any CO shift and cleanup stages. The working catalyst contains, on average, 3–4 nm copper particles, alongside extremely small size of copper clusters stabilized on a defective ZnGa₂O₄ spinel oxide surface, providing hydrogen productivity of 393.6 ml g⁻¹-cat h⁻¹ at 150 °C.