Enhanced Electrocatalysis for Energy-Efficient Hydrogen Production over CoP Catalyst with Nonelectroactive Zn as a Promoter
Enhanced Electrocatalysis for Energy-Efficient Hydrogen Production over CoP Catalyst with Nonelectroactive Zn as a Promoter
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以非电活性锌为促进剂的 CoP 催化剂增强电催化高效节能制氢
DOI：
10.1002/aenm.201700020
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发表时间：
2017-08-09
影响因子：
27.8
通讯作者：
Sun, Xuping
中科院分区：
文献类型：
--
作者：
Liu, Tingting;Liu, Danni;Sun, Xuping
锌是一种无毒物质，具有多种生物学功能，但其对电催化的促进作用却鲜有人研究。本文报道了非电活性锌在酸性和碱性介质中作为CoP催化析氢反应(HER)的有效促进剂的理论预测和实验研究。密度泛函理论计算表明，锌的存在导致了更多的热中性氢吸附自由能，从而提高了其对CoP催化剂的活性。电化学测试表明，在0.5M H_2SO_4和1.0M KOH中，在钛网(ZZ0.08Co0.92P/TM)上制备的纳米管阵列的过电位仅为39 mV和67 mV，其几何催化电流分别为10 mA cm(-2)。对于尿素氧化反应(UOR)，该催化剂的活性也优于CoP/TM，在1.0M氢氧化钾和0.5M尿素中，在0.6V时驱动电流为115 mA cm(-2)。这种双功能电极具有较高的HER和UOR活性，使基于锌钴0.92P/TM的双电极电解槽能够在1.38V的低电压下提供10 mA cm(-2)的节能制氢，并具有很强的长期电化学稳定性。
As a non-toxic species, Zn fulfills a multitude of biological roles, but its promoting effect on electrocatalysis has been rarely explored. Herein, the theoretic predications and experimental investigations that non-electroactive Zn behaves as an effective promoter for CoP-catalyzed hydrogen evolution reaction (HER) in both acidic and alkaline media is reported. Density function theory calculations reveal that Zn doing leads to more thermal-neutral hydrogen adsorption free energy and thus enhanced HER activity for CoP catalyst. Electrochemical tests show that a Zn0.08Co0.92P nanowall array on titanium mesh (Zn0.08Co0.92P/TM) needs overpotentials of only 39 and 67 mV to drive a geometrical catalytic current of 10 mA cm(-2) in 0.5 m H2SO4 and 1.0 m KOH, respectively. This Zn0.08Co0.92P/TM is also superior in activity over CoP/TM for urea oxidation reaction (UOR), driving 115 mA cm(-2) at 0.6 V in 1.0 m KOH with 0.5 m urea. The high HER and UOR activity of this bifunctional electrode enables a Zn0.08Co0.92P/TM-based two-electrode electrolyzer for energy-saving hydrogen production, offering 10 mA cm(-2) at a low voltage of 1.38 V with strong long-term electrochemical stability.