Spontaneous activation behavior of NiSn, an intermetallic catalyst, for hydrogen production via methanol decomposition

Fan, M.*; Xu, Y.*; Sakurai, Junya*; Demura, Masahiko*; Hirano, Toshiyuki*; Teraoka, Yuden; Yoshigoe, Akitaka

International Journal of Hydrogen Energy, 40(37), p.12663 - 12673, 2015/10

https://doi.org/10.1016/j.ijhydene.2015.05.197

The catalytic properties of single-phase NiSn powder in the production of hydrogen via the decomposition of methanol were investigated in isothermal tests at 713, 793, and 873 K. The catalytic activity of NiSn significantly increased with time at 793 and 873 K, but not at 713 K, suggesting that NiSn is spontaneously activated at temperatures above 793 K. At these temperatures, NiSn showed high selectivity for H and CO production and low selectivity for CH, CO, and HO production, indicating that methanol decomposition was the main reaction, and that side reactions such as methanation and water-gas shift reaction were suppressed. Surface analysis revealed that fine NiSn particles were formed during the reaction, accompanied by a small amount of deposited carbon. The formation of these particles was suggested to be the cause for the spontaneous activation of NiSn.

Effects of Impurities on Hydrogen Permeability Through Palladium Alloy Membrane at Comparatively High Pressure and Temperature

; Konishi, Satoshi; Katsuta, Hiroji; Naruse, Yuji

JAERI-M 82-013, 21 Pages, 1982/03

JAERI-M-82-013.pdf:0.53MB

no abstracts in English

Catalytic effect of metal colloid on uranium(V) reduction

Kitatsuji, Yoshihiro; Ouchi, Kazuki; Otobe, Haruyoshi

no journal, , 

Redox behaviors of actinide ions in a low-acid solution are complicated and have been unclear, because they tend to form hydroxide complexes, colloids and precipitates. Recently, autocatalysis of the reduction of U(V) to U(IV) in the solution where U(IV) forms hydroxide colloid was reported; U(IV) colloid formed as reduction product catalyzes the electrolytic reduction of U(V). In this study, possibility of catalysis of Zr(IV) colloid which was analogous of U(IV) colloid on the reduction of U(V) was investigated. When U(VI) was electrolyzed at a constant potential in order to reduce to U(V) in the solution of pH 3.0 containing 10 mM Zr(IV), the increase of the reduction current was observed in initial stage of electrolysis. This results indicates that U(VI) was reduced further to U(IV) without catalysis of U(IV) colloid, and that Zr(IV) colloid also acts as catalyst. Intensity of catalysis depends on concentration of Zr(IV), condition of preparing colloid and acidity of the solution.