摘要
The direct electrochemical synthesis of H_(2)O_(2)from O_(2)is currently the most promising alternative to energyintensive industrial anthraquinone oxidation/reduction methods. However, its widespread use is hampered by the lack of efficient low-cost electrocatalysts. In the current study,oxygenated boron-doped carbon(O-BC) materials were realized via a green synthetic strategy involving polymer dehalogenation and employed as electrode materials for the electrochemical synthesis of H_(2)O_(2)via a 2 e-oxygen reduction.The catalytic activity of the O-BC materials was optimized through systematic variation of the boron source(H_(2)BO_(2))dosage and annealing temperature. Electrochemical measurements revealed that the optimal sample(O-BC-2-650)exhibited a selectivity of 98% for the 2 e-oxygen reduction to H2 O_(2)and an average H_(2)O_(2)production rate of412.8 mmol g_(cat)^(-1) h^(-1)in an H-type alkaline electrolyzer. Density functional theory simulations indicated that the functionalization of active B sites with one oxygen atom provides the lowest Gibbs free energy change(ΔG) of 0.03 e V for the hydrogenation of*O_(2), while functionalization with zero or two O atoms results in much larger ΔG values(0.08 and 0.10 e V,respectively). Thus, this work details a new type of green, lowcost, and metal-free electrocatalyst for H_(2)O_(2)production.
O_(2)通过电化学法直接合成H_(2)O_(2)是目前最有可能替代工业上高耗能的蒽醌氧化/还原法的合成方法,但其一直受限于难以开发出高效且低成本的电催化剂.在此,我们通过聚合物脱卤的绿色策略合成了氧化硼掺杂碳(O-BC)材料,将其用作2e-氧还原反应(ORR)的电极材料,采用电化学的方法制备H_(2)O_(2).通过实验调控硼源(H_(2)BO_(2))的用量和退火温度,优化了O-BC材料的催化活性.电化学测试表明:最佳的O-BC-2-650样品表现出高达98%的H_(2)O_(2)选择性;在H型碱性电解槽中H_(2)O_(2)平均产率为412.8 mmol gcat.^(-1)h^(-1).密度泛函理论计算模拟表明:与一个氧原子相连的硼原子是最佳的活性位点,在吸附O_(2)的氢化过程中获得最低的吉布斯自由能差(ΔG)0.03 e V;而没有与氧原子相连或者与两个氧原子相连的B原子则具有较大的ΔG(分别为0.08和0.10 e V).这项工作详细报道了一种用于生产H_(2)O_(2)的新型绿色低成本的无金属电催化剂的调控合成方法.
作者
Yingna Chang
Jiawei Li
Jun Ma
Yu Liu
Rong Xing
Yaqun Wang
Guoxin Zhang
常营娜;李佳伟;马骏;刘昱;邢蓉;王亚群;张国新(Institute of New Energy on Chemical Storage and Power Sources,College of Applied Chemistry and Environmental Engineering,Yancheng Teachers University,Yancheng 224000,China;Shandong University of Science and Technology,Department of Electrical Engineering and Automation,Qingdao 266590,China;College of Chemical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
基金
financially supported by the National Natural Science Foundation of China (22071137)
the Program for Tsingtao Al-ion Power and Energy-storage Battery Research Team in the University (17-2-1-1-zhc)。
