Hydrogen production via methanol steam reforming using sepiolite-derived Cu-based spherical micro-mesoporous catalysts

Abstract

The development of efficient catalysts is the key challenge in methanol steam reforming (MSR), which is one of the potential technologies for hydrogen production. In this study, a spherical micro-mesoporous support (SMMS) was successfully synthesized using a sepiolite-derived silica source, and subsequently SMMS-supported Cu catalysts with different Cu contents (denoted as xCu/SMMS) and M (M = Fe, Mn or La) promoters (denoted as xCuyM/SMMS) were prepared via an impregnation method. Various characterizations demonstrated that the SMMS with a uniform micro–mesoporous structure and large specific surface area promoted the dispersion of active metals, and an appropriate content of Cu and M promoters could provide adequate reactive metallic sites and abundant oxygen vacancies (V_O) and improve the interactions between the M promoters and Cu. Amongst the as-prepared catalysts, 8Cu2Mn/SMMS exhibited unique Cu–MnO_x interface sites, which could inhibit the excessive oxidation of metallic Cu to supply sufficient active Cu⁺ sites and V_O for MSR. Moreover, under the synergistic effect of V_O, Cu⁰/Cu⁺ and Cu–MnO_x interface sites, it presented the highest methanol conversion (96.66%) and hydrogen yield (94.49%). Furthermore, it exhibited stability up to 35 h of MSR. Additionally, the characterizations of spent catalysts demonstrated that 8Cu2Mn/SMMS possessed excellent oxidation resistance and anti-sinter capability.