Highly efficient conversion of oleic acid to heptadecane without external hydrogen source over atomic layer deposited bimetallic NiPt catalysts

A highly efficient Ni-Pt bimetallic catalyst over Al₂O₃ for the conversion of oleic acid to heptadecane without using external hydrogen source is synthesized by the atomic layer deposition (ALD). The combined characterizations of HAADF-STEM, in-situ XAFS and CO-DRIFTS confirmed that Ni-Pt-ALD formed a Pt-skin structure over the sub-surface Ni particles. With the modification of Ni, the Pt-skin bimetallic particles exhibit excellent activity and selectivity in the upgrade reaction of oleic acid to aviation fuels. The yield of heptadecane reaches 91%, near the theoretical upper limit of the “self-hydrogen supply-consumption”. The remarkable catalytic performance of the Ni-Pt-ALD catalyst demonstrates that the subsurface Ni-modulated Pt skin structure is capable of integrating the dehydrogenation, decarboxylation and hydrogenation reactions. The undesired side reactions such as alkyl chain aromatization and polymerization could be effectively inhibited.