Efficiency NiCu/t-zirconia catalysts for methanol steam reforming: Experimental and DFT insights

Abstract

The development of copper-based catalysts with superior stability, activity, and reduced CO selectivity has been a prominent subject of research in the domain of hydrogen production via methanol steam reforming. In this paper, the bimetallic Ni–Cu catalysts supported by t-ZrO2 were synthesized, with varying concentrations of copper phase being considered. The prepared catalysts were characterized by XRD, XPS, BET, ICP, FESEM, TEM, H2-TPR, EPR and N2O titration, and the results showed that appropriate copper phase concentration and nickel doping obviously decreased the crystal size and promoted the development of pore structure. With the condition of W/M = 3 and LHSV = 5.6 h−1, the catalytic activity revealed the methanol conversion and H2 yield of CNZs were evaluated. The CNZ-4 exhibited optimal performance and stability in the MSR process, with a methanol conversion rate of 100 % and H2 yield of 311 mmol g−1 h−1 at a temperature of 533 K. Given the results that in-situ DRIFTS tests showed, the generation of methyl formate as an intermediate was evaluated. Moreover, further DFT insights pointed out that the ternary surface model showed the best surface adsorption and reaction performance, which provided evidence for the high activity of CNZ catalyst at the molecular level.