Highly active and robust biomimetic ceramic catalyst for oxygen reduction reaction: Inspired by plant leaves. Issue 12 (15th June 2023) - Pang, Shengli
Abstract: Structural instability under working conditions is critical issue that restricts applications of perovskite O2 catalysts in the field of solid oxide fuel cells. Inspired by plant leaves, a biomimetic ceramic catalyst with PrBaCo2 O5+δ 'mesophyll' and Gd0.1 Ce0.9 O1.95 'epidermis' and 'vein' was successfully engineered in this work. The 'epidermis' reduces the polarization resistance of O2 reduction reaction on catalyst surface by ∼24%, and the 'vein' reduces resistance of O 2− transport through cathode layer by ∼65%. Moreover, this biomimetic catalyst increases output power density of the cell by 79% and reverses rapid decay trend of the cell with a 23% increase in power density during first 20 h followed by stabilization at 0.91 W cm −2 (at 750 °C and 0.7 V). This discovery provides new avenue for the development of high-performance O2 catalysts with practical applications and enriches the scientific understanding of catalysis. Graphical abstract: Image 1 Highlights: Inspired by leaves, a biomimetic ceramic catalyst is proposed for SOFCs. The 'epidermis' with a thickness of ∼5 nm reduces the resistance for ORR by ∼24%. The in-situ grown 'vein' reduces the resistance of O 2− transport by ∼65%. The biomimetic catalyst has excellent oxygen catalytic activity and durability. The biomimetic catalyst offers a new strategy for oxygen catalyst development.