Effect of promoters Co and Ru on Ni/CeO2 catalysts in ethanol steam reforming for hydrogen production

Bioethanol is an attractive renewable feedstock for sustainable H 2 production because of its high hydrogen content and ease handling. Among thermochemical routes, ethanol steam reforming (ESR) offers the highest theoretical H 2 yield, yet catalyst deactivation by carbon deposition limits its application. Here, 10 wt% Ni/CeO 2 catalysts promoted with trace amounts of Co or Ru (0.25 wt%) were evaluated for ESR. Both promoters enhanced hydrogen production and reduced coke formation compared with unpromoted Ni/CeO 2 . NH 3 desorption revealed a lower density of acidic sites, consistent with inhibition of ethanol dehydration and coke-forming pathways. In situ DRIFTS revealed that promoters decreased methane formation while favored carbonate and acetate species. Notably, 10Ni/0.25Ru/CeO 2 delivered the highest hydrogen yield and the lowest carbon formation rate (22 mg carbon g cat −1 h −1 ), with only 9 wt% carbon deposition in 6 h of continuous operation, highlighting ultra-low promoter loadings as an efficient and cost-effective strategy for ESR.