A COMPARISON OF HYDROGEN PRODUCTION BY WATER SPLITTING ON THE SURFACE OF α‐, δ‐ AND γ‐Al ₂ O ₃

Abstract

Abstract Water splitting is becoming one of the most important processes for producing green fuel hydrogen. Among various materials, alumina provides the best surface for water splitting to generate green energy hydrogen. Therefore, radiation‐catalytic and radiation‐thermocatalytic activities of the polymorphic forms of Al 2 O 3 (α‐, δ‐, γ‐) in the water decomposition process were studied at various temperatures. It is established that γ‐Al 2 O 3 has relatively high radiation‐catalytic properties in the process of water decomposition. The maximum yields of the radiation‐chemical molecular hydrogen at 873 K for 30 hrs were 4.5, 5.8, and 7.0 N(H 2 )×10 −18 molecules/g for α‐, δ‐ and γ‐Al 2 O 3 ; indicating the best performance of γ‐Al 2 O 3 . The pattern of accumulation of localized states of non‐equilibrium charge carriers in polymorphic forms of γ‐Al 2 O 3 was determined. Furthermore, the proposed mechanisms of energy transfer and lengths of energy transfer in radiation‐heterogeneous processes of water decomposition were determined. The developed method may be used to produce hydrogen fuel on a large scale.