Decoding the Role of Metal‐Oxide Interactions in Hydrogen Optimization through Oxidative Steam Reforming of Ethanol (OSRE)

Abstract This study explores the influence of metal‐oxidic matrix interactions in hydrotalcite‐type structures, achieved through the isomorphic substitution of NiCo, to enhance catalytic performance in the oxidative steam reforming of ethanol (OSRE). By modulating key properties: i) crystalline structure, ii) bimetallic phase dispersion, iii) basic site density, and iv) reducibility, a correlation with catalytic activity is established. Prereduction at 600 °C revealed that increasing NiCo content promotes partial reduction, which intensifies as metal‐matrix interactions weaken, at the expense of basic sites. CO chemisorption experiments confirmed the presence of both semi‐oxidized (Mⁿ⁺) and reduced (M⁰) metal states, with smaller active‐phase loadings favoring highly dispersed particles rich in Mⁿ⁺. These particles exhibited strong interfacial interactions that resisted full metal reduction. Optimal catalytic performance is achieved with 20–30 wt.% NiCo, with an optimal amount of M⁰/Mⁿ⁺, yielding complete ethanol conversion and 60% selectivity to H₂ at 400 °C, as validated by DRIFT and GC analyses. Post‐reaction characterizations highlighted the formation of carbonaceous deposits, which are mitigated by small particle sizes and a high O_II/O_I ratio, as determined by XPS. These findings provide a roadmap for tailoring catalytic systems to maximize efficiency in OSRE applications.