Single-phase Ni3Sn alloy alkali-leached for hydrogen production from methanol decomposition

Abstract

Methanol decomposition over alkali-leached Ni3Sn powder at 513–793 K was investigated. Compared with untreated Ni3Sn, alkali-leached Ni3Sn had high catalytic activity and selectivity toward H2 and CO production above 633 K. A maximum H2 production rate of 100 × 10−3 mol h−1 g-Cat−1 and H2 selectivity above 95% were attained over alkali-leached Ni3Sn at 793 K. Alkali-leached Ni3Sn presented good catalytic activity for 45 h of reaction at 713 K, whereas Ni3Sn had none. The activation energy was calculated, and its values rapidly decreased from Ni3Sn to alkali-leached ones. The improvement was attributed to the formation of Ni nanoparticles less than 100 nm in diameter in the alkali-leaching process, which had high activity for methanol decomposition. The improved catalytic activity favored the gradual formation of fine Ni3Sn particle during the reaction, which served as the active sites for methanol decomposition when the catalytic activity decreased because of carbon deposition on the Ni surface. Results demonstrated that alkali-leached Ni3Sn was a promising potential catalyst for hydrogen production from methanol.