Dong Yan, Komarneni Sridhar
Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, 205 Energy and Environment Laboratory Hastings Rd, University Park, PA, 16802, USA.
Department of Ecosystem Science and Management and Materials Research Institute, The Pennsylvania State University, 204 Energy and Environment Laboratory Hastings Rd, University Park, PA, 16802, USA.
Small Methods. 2021 Jan;5(1):e2000719. doi: 10.1002/smtd.202000719. Epub 2020 Nov 3.
The anodic oxygen evolution reaction (OER) is the bottleneck of water splitting to produce hydrogen due to its sluggish kinetics. In order to lower the energy cost, highly active and cost-efficient OER catalysts need to be used to overcome the OER reaction barrier, especially in neutral pH. Compared to alkaline or acidic electrolytes, pH-neutral or pH-near-neutral electrolytes are considered to be cheaper and safer, and water from rivers and the sea could be used directly under such conditions. However, OER under neutral pH is challenging compared to the OER catalysts for alkaline conditions. Therefore, OER catalysts for neutral or near-neutral pH have not been pursued significantly and, hence, there are limited advances in this area. Here, the progress made in the research and development of earth-abundant heterogeneous catalysts for OER in three pH-neutral or pH-near-neutral systems, namely, the phosphate system, the carbonate system, and the borate system, are systematically reviewed and summarized for the first time. Strategies to develop high-performance OER catalysts for neutral pH are reviewed and summarized. In addition, future challenges and opportunities in this field are discussed, which may shed some light on the future developments of earth-abundant heterogeneous catalysts for OER in neutral or near-neutral pH.
阳极析氧反应（OER）因其缓慢的动力学过程，成为水分解制氢的瓶颈。为降低能源成本，需要使用高活性且经济高效的OER催化剂来克服OER反应势垒，尤其是在中性pH条件下。与碱性或酸性电解质相比，pH中性或近中性电解质被认为更便宜、更安全，在此条件下可直接使用河水和海水。然而，与碱性条件下的OER催化剂相比，中性pH条件下的OER具有挑战性。因此，针对中性或近中性pH的OER催化剂尚未得到大量研究，该领域进展有限。在此，首次系统回顾并总结了在三种pH中性或近中性体系（即磷酸盐体系、碳酸盐体系和硼酸盐体系）中用于OER的储量丰富的非均相催化剂的研发进展。综述并总结了开发用于中性pH的高性能OER催化剂的策略。此外，还讨论了该领域未来的挑战与机遇，这可能为储量丰富的中性或近中性pH条件下用于OER的非均相催化剂的未来发展提供一些启示。
