XAS study of Ni2P/MCM-41 prepared by hydrogen plasma reduction

• Published in: Catalysis today 2013-08, Vol.211, p.126-130
• Main Authors: Sun, Zhichao, Li, Xiang, Wang, Anjie, Wang, Yao, Chen, Yongying, Hu, Yongkang
• Format: Article
• Language: English
• Subjects: Catalysis; catalysts; catalytic activity; Chemistry; Colloidal state and disperse state; crystal structure; Exact sciences and technology; General and physical chemistry; Hydrodesulfurization; hydrogen; Hydrogen plasma reduction; hydrogenation; MCM-41; Ni2P; phosphorus; Porous materials; Temperature-programmed reduction; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; XAS
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2013.01.005

[Display omitted] ► XAS study of Ni2P/MCM-41 prepared by hydrogen plasma reduction (PR) and TPR. ► Ni2P with perfect crystal structure was obtained by the PR method (Ni2P-PR). ► Extra P was found in the lattice of Ni2P prepared by the TPR method (Ni2P-TPR). ► Ni in Ni2P-TPR was more electron-deficient than that in Ni2P-PR. ► Ni2P-TPR showed higher hydrogenation selectivity than Ni2P-PR. Two Ni2P hydrodesulfurization (HDS) catalysts supported over siliceous MCM-41 were prepared by the conventional temperature-programmed reduction method (Ni2P-TPR) and a novel hydrogen plasma reduction method (Ni2P-PR). They were characterized by XRD and XAS. Their catalytic performances were evaluated by HDS of dibenzothiophene. The results indicated that a well dispersed Ni2P phase with crystal structure close to the standard was obtained by the hydrogen plasma reduction. For the catalyst prepared by the temperature-programmed reduction method, extra phosphorus was found in the lattice of Ni2P phase, leading to the lattice distortion, the increase in the NiP coordination number, and the decrease in the NiNi coordination number with lengthening of its bond distance. Ni in Ni2P-TPR was more electron deficient than that in Ni2P-PR, probably due to the electronic interaction between Ni and the extra P present in Ni2P-TPR. Consequently, Ni2P-TPR showed higher hydrogenation selectivity than Ni2P-PR.