The development of non-platinum(Pt) oxygen reduction reaction(ORR) catalysts with high activity and low cost is of great importance for large-scale commercialization of fuel cells. By means of density functional theor...The development of non-platinum(Pt) oxygen reduction reaction(ORR) catalysts with high activity and low cost is of great importance for large-scale commercialization of fuel cells. By means of density functional theory(DFT) computations, we theoretically identified that two-dimensional(2D) iron-porphyrin(Fe-Pp) sheet, in which the active Fe sites are distributed regularly and separately, is an appealing candidate. The pristine Fe-Pp sheet exhibits considerably high catalytic activity and four-electron selectivity for ORR. Especially, the adsorption of ORR intermediates on Fe-Pp sheet can be significantly weakened by the addition of axial cyanogen(CN) ligand, resulting in pronouncedly enhanced ORR activity. More interestingly, the d band center of CN attached Fe-Pp(Fe-Pp-CN) sheet can be further tuned by applying the external tensile or compressive strain, leading to an enhancement or suppression of ORR catalytic performance. In particular, under a small biaxial tensile strain of 2%, the ORR activity of Fe-Pp-CN sheet is even higher than that of Pt and reaches to the top of activity volcano. Our studies open new ways to design effective non-Pt ORR catalysts for fuel cell technology.展开更多
基金supported by the National Natural Science Foundation of China (21403115 and 21522305)the Natural Science Foundation of Jiangsu Province (BK20150045)+1 种基金Innovation Project in Jiangsu Province (KYZZ16-0454)The priority academic program development of Jiangsu higher education institutions
文摘The development of non-platinum(Pt) oxygen reduction reaction(ORR) catalysts with high activity and low cost is of great importance for large-scale commercialization of fuel cells. By means of density functional theory(DFT) computations, we theoretically identified that two-dimensional(2D) iron-porphyrin(Fe-Pp) sheet, in which the active Fe sites are distributed regularly and separately, is an appealing candidate. The pristine Fe-Pp sheet exhibits considerably high catalytic activity and four-electron selectivity for ORR. Especially, the adsorption of ORR intermediates on Fe-Pp sheet can be significantly weakened by the addition of axial cyanogen(CN) ligand, resulting in pronouncedly enhanced ORR activity. More interestingly, the d band center of CN attached Fe-Pp(Fe-Pp-CN) sheet can be further tuned by applying the external tensile or compressive strain, leading to an enhancement or suppression of ORR catalytic performance. In particular, under a small biaxial tensile strain of 2%, the ORR activity of Fe-Pp-CN sheet is even higher than that of Pt and reaches to the top of activity volcano. Our studies open new ways to design effective non-Pt ORR catalysts for fuel cell technology.
