Efficient deoxygenation of methyl esters to hydrocarbons on Al2O3 supported Ni-Sn intermetallic compounds

• Published in: Molecular catalysis 2023-04, Vol.540, p.113056, Article 113056
• Main Authors: Shu, Sihao, Wang, Zhongze, Zhang, Xing, Shi, Haonan, Feng, Shangzhen, Chen, Jixiang
• Format: Article
• Language: English
• Subjects: C-C bond hydrogenolysis; Decarbonylation/decarboxylation; Fatty acid methyl ester; Hydrocarbon; Hydrodeoxygenation; Ni-Sn intermetallic compounds
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2023.113056

•Synergetic effect between Ni and Sn facilitates hydrodeoxygenation pathway.•C-C bond hydrogenolysis and methanation are remarkably suppressed on Ni-Sn IMCs.•Yield of hydrocarbons reaches ∼99% on Ni3Sn2/Al2O3. Al2O3 supported Ni-Sn alloy (Ni/Sn atomic ratio of 6) and Ni3Sn, Ni3Sn2 and Ni3Sn4 intermetallic compounds (IMCs) were prepared by co-precipitation method for the deoxygenation of fatty acid methyl esters to produce hydrocarbons. In comparison with metallic Ni, the catalytic evaluation and methyl propionate-TPD/TPSR results reveal that Ni-Sn IMCs remarkably inhibit the decarbonylation/decarboxylation pathway, C-C bond hydrogenolysis and methanation while promote the hydrodeoxygenation pathway, subsequently enhancing the yield of aiming hydrocarbons. Therein, 20%Ni3Sn2/Al2O3 has the best performance, and the hydrocarbons yield reach about 99% in the deoxygenation of methyl octanoate and methyl palmitate. We suggest that the geometric and electronic effects of Sn contribute the excellent performance of Ni-Sn IMCs, and there is synergetic effect between Ni and Sn sites for the activation of C-O/C=O bond, for which a suitable Ni-Sn atomic spacing is very important. Finally, the catalyst stability and deactivation were also investigated. [Display omitted]