Indium promoted Cu/SiO2 catalyst for improved hydrogen productivity in the steam reforming of methanol

The use In as an effective promoter for the methanol steam reforming (MSR) reaction with Pt or Pd supported catalysts is well known [1]. The M-In interactions play a crucial role for the improvement of the H2 and CO2 selectivity, as well as CO suppression. However, the high cost of these noble metals is an important penalty for the development of new catalysts for sustainable hydrogen production. Alternatively, Matsumura et al. reported Cu-In catalysts for MSR at different In loadings showing a high stability in reaction conditions together with a dramatic loss of activity due to the deactivation of the Cu active phase by indium oxide [2]. We report herein the synthesis of a silica-supported Cu-In bimetallic catalyst by urea-assisted co-precipitation of the metal precursors. By this approach Cu exposure was preserved due to the small size of the Cu nanoparticles (2.5 nm) and to the homogeneous dispersion of the indium oxide phase. The Cu-In/SiO2 catalyst promoted the MSR by producing an almost stoichiometric hydrogen stream (H2/CO2 molar ratio of 3) already at reaction temperatures as low as 220 °C. For comparison, at the same conditions, the Cu/SiO2 catalysts exhibited a lower H2 selectivity (H2/CO2 molar ratio of 2.7). A series of characterization tools, including XPS, XRPD and HRTEM-EDX along with H2-TPR, CO-TPR and N2O titrations, allowed us to unravel the superior performance of this Cu-In catalyst.