Modulating valence band to enhance the catalytic activity of Co-Cr-B/NG for hydrolysis of sodium borohydride

Abstract

In this work, amorphous Co-Cr-B/NG catalysts were prepared by the chemical reduction method. A descriptor of "valence band center" was introduced to the NaBH4 hydrolysis reaction to investigate the relationship between the valence band and the catalytic activity of amorphous Co-Cr-B/NG catalysts. The outcomes show that the valence band center of the Co-Cr-B/NG hybrids has been significantly changed after the Cr content is regulated by the preparation process, which can facilitate the modulation of the electronic structure of the catalysts. The hydrogen release rate shows a shape of a volcano with the valence band center. The hydrolysis performance test results of the optimum catalyst demonstrated that the hydrogen release rate of NaBH4 water at 25 °C was 2231.7 mL·min−1·g−1 with an activation energy of 38.41 KJ·mol−1, according to the volcano curve.