Steam reforming and oxidative steam reforming for hydrogen production from bioethanol over Mg2AlNiXHZOY nano-oxyhydride catalysts

Mg2AlNiXHZOY nano-oxyhydrides formation is evidenced during pre-treatment in H2 at 450 °C of Mg2AlNiXOY nano-compounds leading to highly performant catalysts in ethanol conversion and H2 formation, particularly at low temperature, through catalytic steam reforming (SRE) and oxidative steam reforming (OSRE). Total conversion of ethanol is obtained in SRE and OSRE with high stability. A higher production of H2 (60 L h−1 gcat−1) can be achieved at a reaction temperature of 300 °C in OSRE conditions compared to SRE (10 L h−1 gcat−1) mainly because of a beneficial use of a high concentration of ethanol (14 mol%) in presence of O2. Moreover, carbon formation is decreased and a much lower input of energy of 50 °C is used to get a temperature of 300 °C when O2 is added. Different physico-chemical characterizations and in particular in H2 (TPR, H2-XRD, INS) and after tests allow to conclude that the presence of Ni2+ cations in strong interaction with other cations, anionic vacancies and hydride species on and inside the solid play an important role in the catalytic performance (conversion and selectivity) and stability.