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

Abstract Mg 2 AlNi X H Z O Y nano-oxyhydrides formation is evidenced during pre-treatment in H 2 at 450 °C of Mg 2 AlNi X O Y nano-compounds leading to highly performant catalysts in ethanol conversion and H 2 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 H 2 (60 L h −1  g cat −1 ) can be achieved at a reaction temperature of 300 °C in OSRE conditions compared to SRE (10 L h −1  g cat −1 ) mainly because of a beneficial use of a high concentration of ethanol (14 mol%) in presence of O 2 . 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 O 2 is added. Different physico-chemical characterizations and in particular in H 2 (TPR, H 2 -XRD, INS) and after tests allow to conclude that the presence of Ni 2+ 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.