Promotion of a copper–zinc catalyst with rare earth for the steam reforming of methanol at low temperatures

The co-precipitation method was used to prepare a reference catalyst composed of copper/zinc oxide (Cu/Zn), as well as a series of Cu/Zn catalysts promoted by monocomponent rare earth (Cu/mRE–Zn) and bicomponent rare earth (Cu/bRE–Zn). The prepared catalysts were tested in a packed-bed reactor in the production of hydrogen via the steam reforming of methanol (SRM). The experimental SRM performance of the prepared catalysts was compared according to three fundamental criteria: the minimum temperature required for 95% conversion of methanol (T95), the selectivity of CO in the hydrogen-rich gas produced (SCO), and the decay rate (k) at T95. The catalysts followed the performance trend Cu/bRE–Zn > Cu/mRE–Zn > Cu/Zn in the SRM tests. Distinctly high SRM performance, i.e., low values for T95 (210 °C), SCO (0.04%), and k (negligible in 16 h), was observed using the Cu/bRE–Zn catalyst. The high performance of Cu/bRE–Zn catalysts was attributed to good adhesion of RE oxides to both CuO and ZnO.