Ga ₂ O ₃ -Modified Cu–ZnO Catalysts for Efficient Hydrogen Production from Aqueous-Phase Reforming of Methanol

Ensuring safer and more satisfactory hydrogen (H2) production from aqueous-phase reforming of methanol (APRM) is crucial for automotive, marine, and aerospace applications. However, nonprecious metal catalysts face challenges in realizing efficient methanol (CH3OH) dehydrogenation and effective carbon monoxide (CO) suppression for APRM without a strong base. In this work, we synthesized Ga2O3-modified Cu–ZnO catalysts with carbon encapsulation, leading to a uniform Cu dispersion. The optimized 12 wt % GCZ-2.0-C450 catalyst exhibits good performance over a wide temperature range (130–210 °C). It achieves a high H2 production rate of 101.2 μmol/gcat/s and low CO selectivity (0.07%) at 210 °C with long-term stability, surpassing the reported Cu- and Pt-based catalysts in APRM. Density functional theory calculations indicate that the Ga2O3 introduction significantly reduces the Gibbs energy of the rate-determining step of *CH3O + *H → *CH2O + *H2, dropping from 1.25 to 0.60 eV. Meanwhile, the adsorption energy of the generated *H2 decreases from −2.92 to −0.13 eV, which facilitates the release of gaseous H2.