Abstract:

Under the background of "double carbon", efficient and clean hydrogen energy has become an important alternative to traditional fossil energy, and electrolysis of water to produce hydrogen is a key technology to be conquered. At present, the catalysts with high catalytic activity for efficient hydrogen evolution are mainly precious metals. However, the high cost and scarcity of precious metals seriously hinder their large-scale application in clean energy technology. Therefore, the development of efficient, durable, cheap and earth-rich electrocatalysts is of good importance to realize these technologies. In this work, a novel ZnCo-MOF with unique polyhedral morphology was synthesized by using ZnCo-MOF-74 NPs as precursor under the treatment of acid solution. Then, CoP-doped hierarchical porous carbon with regular morphology (H-CoP/C) was obtained through a stepwise calcination and phosphorylation process. The results showed that hierarchical porous carbon as a carrier could not only support more active sites, but also facilitate the exposure of active sites, the conductivity of materials and the mass transfer in the catalytic process. With favorable structural characteristics and sufficient active sites, the obtained electrocatalyst H-CoP/C had excellent HER performance in alkaline media. Only 168mV overpotential was required to drive the current density of 10mA/cm², which was superior to most non-precious metal electrocatalysts.

Key words: electrolysis of water, hydrogen evolution reaction, CoP, metal-organic framework, hierarchical porous carbon

摘要：

在“双碳”背景下，高效、清洁的氢能源成为代替传统化石能源的重要选择，而电解水产氢是开发氢能源需要攻克的关键技术之一。目前，电解水产氢催化活性较高的催化剂主要以贵金属催化剂为主，然而贵金属价格高昂、资源稀缺严重阻碍了它们在清洁能源领域的大规模应用。因此，开发高效、耐用、廉价和地球资源丰富的电催化剂是实现电解水产氢的迫切需求。本文以无定形的锌钴双金属有机框架为前体，通过酸溶液处理制备了一种具有独特多面体结构的新型骨架材料（ZnCo-MOF），然后通过逐级碳化磷化过程，在保留原有形态的基础上得到了CoP负载的具有规则形貌的多级孔碳（H-CoP/C）。研究表明：多级孔碳作载体不仅能够负载更多活性位点，而且有利于活性位点的暴露、材料的导电性和催化过程中的传质。凭借有利的结构特征、充足的活性位点，所获得的电催化剂H-CoP/C在碱性介质中展现出优异的HER性能，驱动10mA/cm²的电流密度只需168mV的过电位，优于大多数的非贵金属电催化剂。

关键词: 电解水, 析氢, CoP, 金属有机骨架, 多级孔碳