Modulating Cu-O-Zr interfaces on high-roughness MgO surface for reinforced hydrogen production from sorption-enhanced steam reforming of methanol

Abstract

Sorption-enhanced steam reforming of methanol (SE-SRM) offers a promising route for high-quality hydrogen production with in situ CO₂ capture; however, achieving an optimal balance between catalytic activity and CO₂ uptake capability, while ensuring catalyst stability, remains a significant challenge. In this study, a series of Zr-doped (0 wt%, 5 wt%, 15 wt%, 25 wt%) Cu-MgO catalytic sorbents are synthesized for SE-SRM. At 180℃, the hydrogen concentration and yield reach nearly 100 % and 10.35 μmol·g⁻¹·s⁻¹. Moreover, the catalytic sorbent basically retains its catalytic activity and CO₂ uptake capacity after 30 cycles with merely slight deactivation. Results demonstrate that the doped Zr, presents as tetragonal ZrO₂, enhances metal-support interactions with the formation of a Cu-O-Zr interfacial structure, promoting Cu nanocluster dispersion and altering the Cu⁺/Cu⁰ distributions. Zr doping also enables the modulation of the medium-strong basic sites. Moreover, the AFM and TEM confirmed the formation of high-roughness MgO surface on the substrate, thereby facilitating CO₂ diffusion and adsorption. DFT calculation results further confirm the advantages of Zr-doped Cu-MgO catalytic sorbents due to its stronger capability on CH₃OH activation and CO₂ adsorption.