摘要
CONSPECTUS:Clean energy conversion technologies can power progress for achieving a sustainable future,while functional materials lie at the core of these technologies.In particular,highly efficient electrocatalysts that are also cost-effective are of utmost concern in the development of several clean energy conversion technologies.These include fuel cells and water electrolyzers.It is well recognized that electrocatalysts are needed to greatly accelerate the kinetics of key electrochemical reactions involved in these energy conversion technologies.Perovskite oxides are being used as key materials that have provided impetus in the development of energy conversion and storage,in view of their flexibility in elemental composition.Over 90%of known elements are able to become incorporated into their metal cation sites,resulting in diversified properties.Several strategies can be used to tailor the intrinsic properties of perovskites,leading to the optimization of their catalytic activity for electrochemical reactions.Cation deficiency has received particular attention as a unique strategy since no other elements or phases are involved,thereby avoiding the unknown effects of foreign elements or phases on performance.In this Account,we present our recent contributions to the study of cation-deficient perovskite oxides in the context of their applications in clean energy conversion.This includes oxygen separation through mixed conducting membranes,which is important for clean combustion,electricity generation through both solid oxide fuel cells using chemical fuels and dye-sensitized solar cells,and hydrogen production from water through both solid oxide electrolysis cells at high temperatures and water electrolyzers at room temperature.The journey begins with a discussion of the defect chemistry and charge compensation mechanisms present in cationdeficient perovskite oxides and then we propose benefits from the cation deficiency strategy that can optimize the materials’properties in terms of electrical conductivity,phase structure,oxygen vacancy concentration,oxygen ion and cation diffusion properties,and proton transportation.Thus,both the sintering behavior of materials and their catalytic activity is dramatically improved for key reactions such as oxygen reduction,oxygen evolution,hydrogen evolution,and iodine reduction.Accordingly,the remarkable increases in performance of the aforementioned energy conversion systems are achieved through adopting cationdeficient perovskites.At the end of this Account,we conclude with some suggestions on how future research can broaden the applications for cation-deficient perovskites.
基金
supported by the Australian Research Council(ARC)Discovery Project Grants DP200103332 and DP200103315
partially supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20190965).
作者简介
Chao Su,received her Ph.D.in Chemical Engineering at Nanjing Tech University,China,in 2012.She was an Australian Research Council(ARC)Discovery Early Career Researcher Award(DECRA)Fellow.Currently,she is a professor at Jiangsu University of Science and Technology.Her research focuses on the development of functional materials for electrochemical energy conversion and storage technologies,such as fuel cells,metal−air batteries,and water splitting;Wei Wang,is a professor of chemical engineering at Nanjing Tech University,China.He obtained his Ph.D.in Chemical Engineering at Nanjing Tech University in 2013 and then worked as a postdoc at Curtin University.His current research interests are focused on the design and development of functional materials for various energy conversion technologies such as fuel cells,solar cells,and water splitting;Corresponding Author:Zongping Shao,is a John Curtin Distinguished Professor at Curtin University,Australia,and also a professor at Nanjing Tech University,China.He obtained his Ph.D.from Dalian Institute of Chemical Physics,China,in 2000.He worked as a Visiting Scholar at Institut de Researches Sur La Catalyse,CNRS,France,and then a Postdoctoral Fellow at California Institute of Technology,USA,from 2000 to 2005.His current research interests include fuel cells,lithium-ion batteries,metal-air batteries,solar cells,and oxygen-permeable membranes.He has been recognized as a Highly-Cited Researcher by Clarivate Analytics since 2017.orcid.org/0000-0002-4538-4218,Email:zongping.shao@curtin.edu.au。
