Abstract

It is still a significant challenge to replace noble metal based catalysts by non-noble metal-based, highly efficient and earth-abundant catalysts in the H₂ generation upon hydrolysis of sodium borohydride. Herein, we first design and synthesize the highly selective and heterogeneous Co_xW_y nanocomposites from ZIF-67 as robust catalysts for H₂ production upon the hydrolysis of sodium borohydride. Among them, the Co_0.45W_0.55 nanocatalyst exhibits the highest TOF of 1770 mL_H2 g_cat⁻¹ min⁻¹ (the TOF related to only cobalt nanoparticles 8401 mL_H2 g_Co⁻¹ min⁻¹) over pure ZIF-67 or W nanoparticles and other ones. In addition, the Co_0.45W_0.55 catalyst has been successfully recycled at least 5 times without any significant activity loss, although the W (VI) has been partly reduced to W (V), W (IV) and W (0) in the hydrolysis of sodium borohydride. This stability is taken into account by the highly active Co species rather than the activity of W itself. Based on the results obtained, we have shown that Co_0.45W_0.55 nanocomposite can be a potential candidate for the replacement of a noble metal catalyst for H₂ generation.

Graphic Abstract

中文翻译：

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ZIF-67的Co 0.45 W 0.55纳米复合材料：NaBH 4水解后生成H 2的高效多相催化剂

摘要

在硼氢化钠水解时，在H ₂生成中，用非贵金属基高效和富土催化剂来代替贵金属基催化剂仍然是一个重大挑战。在这里，我们首先设计和合成ZIF-67的高选择性，多相Co _x W _y纳米复合材料，作为硼氢化钠水解后生产H _2的稳健催化剂。其中，Co _0.45 W _0.55纳米催化剂表现出最高的TOF为1770 mL _H2 g _cat ^-1 min ^-1（仅与钴纳米颗粒8401 mL _H2 g _Co有关的TOF在纯ZIF-67或W纳米粒子和其他纳米粒子上^-1 min ^-1）。此外，尽管在实验过程中W（VI）已部分还原为W（V），W（IV）和W（0），但Co _0.45 W _0.55催化剂已成功回收至少5次而没有任何明显的活性损失。硼氢化钠的水解。高活性的Co物种而不是W本身的活性考虑了这种稳定性。基于获得的结果，我们已经表明，Co _0.45 W _0.55纳米复合材料可以替代H ₂生成的贵金属催化剂。

图形摘要