Room Temperature Hydrogen Production from Ethanol over CeNi_XH_ZO_Y Nano‐Oxyhydride Catalysts

Abstract

CeNiXHZOY nano‐oxyhydride catalysts were developed for the highly efficient sustainable hydrogen production from ethanol and water in the oxidative steam reforming reaction. After an in situ treatment in hydrogen in the temperature range of 200–300 °C, the cerium–nickel binary mixed oxides became hydrogen reservoirs, which were called oxyhydrides, in the presence of hydrogen species of the hydride nature in the anionic vacancies of mixed oxides. A novel technology was developed for the room temperature hydrogen production by using the chemical energy released from the reaction between CeNiXHZOY nano‐oxyhydride catalysts and oxygen, which completely converted ethanol specifically at 60 °C (oven temperature) and simultaneously produced hydrogen, carbon dioxide, and carbon monoxide along with small amounts of methane and ethanal. CeNiXHZOY nano‐oxyhydride catalysts demonstrated excellent catalytic stability, which was attributed to the graphitic filamentous carbon formed during the reaction. The unique activation phenomenon of the reaction (a huge variation in the temperature between the catalyst bed and the oven) was demonstrated in detail. Finally, the correlations among the catalyst properties, the catalytic performances, and the characterizations were thoroughly discussed.

Neutron Scattering Investigations of Hydride Species in Heterogeneous Catalysis

“…Further experimentation on OSRE, by varying the amount of Ni in the CeNi x H z O y catalyst, proved that the best catalyst was that with x= 1. If the concentration of Ni in the catalyst was reduced (Ni/Ce=0.5), the interaction of hydrogen with Ni 0 disappeared (as measured by INS), which was correlated with the high proportion of a solid solution of Ce and Ni in this catalyst …”

ChemInform Abstract: Role of the Interface in Base‐Metal Ceria‐Based Catalysts for Hydrogen Purification and Production Processes

“…As ingular case was the use of hydrogen as am obile species with strongi nfluence in the oxide network, but at positions affecting simultaneously to Ni and, as ac onsequence, to the activityo ft he system in ethanol or the so-called auto-thermal (in the presence of oxygen) ethanol-reforming reactions. [95,96] In theses tudies, the authors used neutron scatteringt op rovide evidenceo ft he hydrogen physicochemical properties in the system and postulated its key role for hydrogen abstraction of the ethanol molecule as ak inetically significant step.…”

Biomass-derived Platform Molecules Upgrading through Catalytic Processes: Yielding Chemicals and Fuels

“…The endothermic SRE reaction (673-973 K) extracts more hydrogen atoms . Different types of nickel-based catalysts such as CeNixOy (0 x ≤ 5) 55) 59) and NixMg2AlOy (0 x ≤ 12) 60),61) compounds we developed revealed as particularly efficient at low temperature. Well tuning the catalyst preparation, formulation, as well as the activation procedure and the reaction conditions enable obtaining a high and stable activity even when some solid carbon is formed.…”

“…H2 is produced from ethanol in a sustainable way by taking advantage of the chemical energy produced by the reaction between hydride species stored in the nano-oxyhydride catalysts and O2 in complement to the exothermic reaction between ethanol and O2 58) . Not only the CeNiHzOy (20 wt% Ni) nano-oxyhydride catalyst, but also the CeNixHzOy oxyhydride family exhibited a catalytic activity in the OSRE reaction, which depends on the Ni content 59) . Ethanol is completely converted on the CeNixHzOy catalysts with various Ni contents.…”