Yang Xuetao, Ma Yanfang, Liu Yang, Wang Keke, Wang Yanqiu, Liu Min, Qiu Xiaoqing, Li Wenzhang, Li Jie
School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 China.
Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083, China.
ACS Appl Mater Interfaces. 2021 May 5;13(17):19864-19872. doi: 10.1021/acsami.0c22623. Epub 2021 Apr 20.
Electrochemical nitrogen reduction reaction (NRR) is a promising method for synthesizing ammonia (NH). However, due to the extremely strong N≡N bond and the competing hydrogen evolution reaction (HER), the electrochemical NRR process remains a great challenge in achieving a high NH yielding rate and a high Faradaic efficiency (FE). Recently, either Bi-based or W-based catalysts have been used in N fixation due to lower HER activity. To further promote N activation, we develop a simple protocol to introduce and adjust the crystal defects in the host lattice of BiWO nanoflowers via adjusting the amount of Ce dopant (denoted as Ce-BiWO, where represents the designed mole percentage of Ce). At -0.20 V versus the reversible hydrogen electrode (RHE), 10%Ce-BiWO manifests a high NH yielding rate (22.5 μg h mg), a high FE (15.9%), and excellent electrochemical and structure durability. Its performance is better than most previously reported Bi-based and W-based electrocatalysts for NRR in aqueous solutions. According to density functional theory (DFT) calculations, the introduction of crystal defects into BiWO can strengthen the adsorption and activation of N, thus leading to a significant increase in NRR activity.
电化学氮还原反应（NRR）是一种很有前景的合成氨（NH₃）的方法。然而，由于N≡N键极强以及存在竞争性析氢反应（HER），电化学NRR过程在实现高氨产率和高法拉第效率（FE）方面仍然面临巨大挑战。最近，由于较低的HER活性，铋基或钨基催化剂已被用于氮固定。为了进一步促进氮活化，我们开发了一种简单的方法，通过调整铈掺杂剂的量（表示为Ce-BiWOₓ，其中x代表设计的铈摩尔百分比）来引入和调节BiWOₓ纳米花主体晶格中的晶体缺陷。相对于可逆氢电极（RHE）在-0.20 V时，10%Ce-BiWOₓ表现出高氨产率（22.5 μg h⁻¹ mg⁻¹）、高法拉第效率（15.9%）以及优异的电化学和结构耐久性。其性能优于大多数先前报道的用于水溶液中NRR的铋基和钨基电催化剂。根据密度泛函理论（DFT）计算，在BiWOₓ中引入晶体缺陷可以增强对氮的吸附和活化，从而导致NRR活性显著提高。
