First Principles Design of Active and Durable Catalysts Toward Oxygen Reduction and Evolution Reactions

Design of Active and Durable Catalysts with Non-precious Materials for oxygen reduction and Evolution Reactions: First Principles Prediction and Experimental Validation

Byungchan Han¹, Jeemin Hwang¹

¹Department of Chemcal & Biomolecular Engineering, Yonsei University, Seoul, 03722, Korea

bchan@yonsei.ac.kr

Using first-principles density functional theory (DFT) calculations and experimental materialization, we design highly active and durable catalysts toward oxygen reduction reaction (ORR) with nonprecious Cu@N-C materials. DFT calculations indicate that encapsulated Cu metal by N-doped carbon shells is a promising electrocatalyst for ORR. To validate the prediction we synthesize three different types of catalysts with various applied processes: (i) hydrothermally treated “Cu@N-C(hydro)”, (ii) “Cu@N-C(heat)” heat-treated at T = 1000 °C for 2 h, and (iii) “Cu@N-C(CO₂)” oxidized by CO₂ for 15 min at T = 1000 °C. It is shown that applying the CO₂ treatment can be a key process controlling electronic structures and shell thickness of the materials leading the high ORR catalytic performance.

 To alleviate the substantial overpotential problem in water splitting process storing the energy in fuels of O₂ and H₂ we develop hexagonal perovskite oxide with a transition metal of mixed oxidation states. Both computational prediction and experimental measurements consistently show that its performance is better than IrO2.

Reference:

Jeemin Hwang, Byungchan Han et al., JACS, 138, 3541-3547 (2016)

Seung Hyo Noh, Byungchan Han et al., J. Mater. Chem. A, 3, 22031-22034 (2015)

Seung Hyo Noh, Byungchan Han et al., Nano Research, 8(10), 3394-3403 (2015)