Journal Article

Effects of the Carbon Support Doping with Nitrogen for the Hydrogen Production from Formic Acid over Ni Catalysts

Bulushev, Dmitri A., Stonkus, Olga A., Bulusheva, Lyubov G., Nishchakova, Alina D., Okotrub, Alexander V., Ishchenko, Arcady V., Asanov, Igor P.

2019

Overview

Porous nitrogen-doped and nitrogen-free carbon materials possessing high specific surface areas (400–1000 m2 g−1) were used for deposition of Ni by impregnation with nickel acetate followed by reduction. The nitrogen-doped materials synthesized by decomposition of acetonitrile at 973, 1073, and 1173 K did not differ much in the total content of incorporated nitrogen (4–5 at%), but differed in the ratio of the chemical forms of nitrogen. An X-ray photoelectron spectroscopy study showed that the rise in the synthesis temperature led to a strong growth of the content of graphitic nitrogen on the support accompanied by a reduction of the content of pyrrolic nitrogen. The content of pyridinic nitrogen did not change significantly. The prepared nickel catalysts supported on nitrogen-doped carbons showed by a factor of up to two higher conversion of formic acid as compared to that of the nickel catalyst supported on the nitrogen-free carbon. This was related to stabilization of Ni in the state of single Ni2+ cations or a few atoms clusters by the pyridinic nitrogen sites. The nitrogen-doped nickel catalysts possessed a high stability in the reaction at least within 5 h and a high selectivity to hydrogen (97%).

• Publisher: MDPI AG
• Subject: Acids / Carbon dioxide / Catalysis / Chemical vapor deposition / Decomposition / formic acid decomposition / Graphene / Hydrogen / hydrogen production / Hydrogenation / Nanoparticles / nickel catalyst / Nitrogen / nitrogen doping / porous carbon support