Halba Dikeshwar, Pakhira Srimanta
Theoretical Condensed Matter Physics and Advanced Computational Materials Science Laboratory, Department of Physics, Indian Institute of Technology Indore (IIT Indore), Simrol, Khandwa Road, Indore, Madhya Pradesh, 453552, India.
Theoretical Condensed Matter Physics and Advanced Computational Materials Science Laboratory, Centre for Advanced Electronics (CAE), Indian Institute of Technology Indore, Simrol, Khandwa Road, Indore, Madhya Pradesh, 453552, India.
ACS Omega. 2024 Aug 6;9(33):35614-35626. doi: 10.1021/acsomega.4c03544. eCollection 2024 Aug 20.
The O reduction reaction (ORR) occurring at cathodes is a critical reaction in many electrochemical energy-converting devices such as fuel cells. The reaction kinematics of the ORR is generally very slow with high overpotentials and needs to be enhanced by using an efficient electrocatalyst. The highly recognized Pt-based electrocatalyst needs to be replaced with a low-cost non-noble metal-based electrocatalyst for catalyzing the ORR. We theoretically studied the structural and electronic properties of 3D bulk LaNiO perovskite. We have cleaved the (0 0 1) surface from 3D LaNiO, which has a zero band gap ( ), to create 2D monolayer LaNiO computationally and studied its electronic properties. Our study demonstrates that the 2D monolayer LaNiO is a suitable candidate for catalyzing the ORR because of its high catalytic activity with a tiny electronic band gap of 0.25 eV. We explored the ORR mechanism on the 2D monolayer LaNiO perovskite by inspecting each intermediate. Our present findings show that the 2D monolayer LaNiO can efficiently catalyze the ORR through a four-electron (4e) reduction reaction due to the excellent catalytic activity of its basal plane, which accords with the experimental findings. The change in Gibbs free energy (Δ) calculations of various intermediate steps of the ORR demonstrates that all reaction steps are spontaneous and thermodynamically favorable. The 2D monolayer LaNiO perovskite can be a potential candidate for catalyzing the ORR efficiently. This study helps to enable the development of high-activity, stable 2D perovskites for use in future solid oxide fuel cells and related applications in green energy technologies.
发生在阴极的氧还原反应（ORR）是许多电化学能量转换装置（如燃料电池）中的关键反应。ORR的反应动力学通常非常缓慢，过电位很高，需要使用高效的电催化剂来增强。高度认可的基于铂的电催化剂需要被低成本的非贵金属基电催化剂取代，以催化ORR。我们从理论上研究了三维块状LaNiO钙钛矿的结构和电子性质。我们从具有零带隙（ ）的三维LaNiO上切割出（0 0 1）表面，通过计算创建二维单层LaNiO，并研究其电子性质。我们的研究表明，二维单层LaNiO是催化ORR的合适候选材料，因为它具有高催化活性，电子带隙仅为0.25 eV。我们通过检查每个中间体来探索二维单层LaNiO钙钛矿上的ORR机理。我们目前的研究结果表明，由于其基面具有优异的催化活性，二维单层LaNiO可以通过四电子（4e）还原反应有效地催化ORR，这与实验结果一致。ORR各个中间步骤的吉布斯自由能（Δ）变化计算表明，所有反应步骤都是自发的，在热力学上是有利的。二维单层LaNiO钙钛矿可能是高效催化ORR的潜在候选材料。这项研究有助于开发用于未来固体氧化物燃料电池及绿色能源技术相关应用的高活性、稳定的二维钙钛矿。
