Zhang Jing, Tian Xiaoyin, Liu Mingjie, Guo Hua, Zhou Jiadong, Fang Qiyi, Liu Zheng, Wu Qin, Lou Jun
Department of Materials Science & Nanoengineering , Rice University , Houston , Texas 77005 , United States.
Center for Functional Nanomaterials (CFN) , Brookhaven National Laboratory , Upton , New York 11973 , United States.
J Am Chem Soc. 2019 Dec 11;141(49):19269-19275. doi: 10.1021/jacs.9b02501. Epub 2019 Nov 21.
Dinitrogen conversion to ammonia via electrochemical reduction with over 10% Faradaic efficiency is demonstrated in this work. Co-doped MoS polycrystalline nanosheets with S vacancies as the catalysts are loaded onto carbon cloth by hydrothermal growth from Mo, Co, and S precursors. A sulfur vacancy on the MoS basal plane mimicking the natural Mo-nitrogenase active site is modified by Co doping and exhibits superior dinitrogen-to-ammonia conversion activity. Density-functional simulation reveals that the free energy barrier, which can be compensated by applied overpotential, is reduced from 1.62 to 0.59 eV after Co doping. Meanwhile, dinitrogen tends to be chemically adsorbed to defective MoS, which effectively activates the dinitrogen molecule for the dissociation of the N≡N triple bond. This process is further accelerated by Co doping, resulting from the modulation of Mo-N bonding configuration.
在这项工作中，展示了通过电化学还原将二氮转化为氨，法拉第效率超过10%。以具有硫空位的共掺杂MoS多晶纳米片作为催化剂，通过从Mo、Co和S前驱体进行水热生长，将其负载在碳布上。通过Co掺杂对MoS基面模拟天然钼固氮酶活性位点的硫空位进行修饰，表现出优异的二氮转化为氨的活性。密度泛函模拟表明，通过施加过电位可以补偿的自由能垒在Co掺杂后从1.62 eV降低到0.59 eV。同时，二氮倾向于化学吸附到有缺陷的MoS上，这有效地激活了二氮分子以解离N≡N三键。Co掺杂进一步加速了这一过程，这是由Mo-N键构型的调制导致的。
