Catalytic performance of Pt-promoted cobalt-based catalysts for the steam reforming of ethanol

In this study, Pt-promoted Co_x/ZrO₂ catalysts (including 1.5 wt% Pt and Co loading of 0.75, 1.5, 3.0, 6.0, 9.0, 12, 24 and 48 wt%, respectively) were prepared by the incipient wet impregnation method for hydrogen production by steam reforming of ethanol (SRE). Evaluation of catalytic activities and products distribution toward the SRE reaction were carried out in a fixed-bed reactor with 100 mg of catalyst under an H₂O/EtOH molar ratio of 13.0 and gas hourly space velocity (GHSV) of 22,000 h⁻¹. The results revealed that the optimal loading of cobalt could enhance the capacities of catalytic performance and C–C scission, further raised the yield of hydrogen (YH₂)$\left({\text{Y}}_{{\text{H}}_2}\right)$ and lowered the deposited carbon, CH₄ and CO side-products due to the combination effect of cobalt and platinum. The Pt_1.5Co₁₂/ZrO₂ catalyst exhibited superiority in the SRE reaction, where complete conversion of ethanol was achieved at 275 °C. The (YH₂)$\left({\text{Y}}_{{\text{H}}_2}\right)$ approached 4.95, and only minor CO (<2%), CH₄ (<4%), and carbon deposition (<0.5%) were detected at 500 °C. In addition, the ethanol conversion still remained complete, and the selectivity of hydrogen exceeded 70% during a 116 h time-on-stream test under the same condition.