Replacing oxygen evolution with sodium sulfide electro-oxidation toward energy-efficient electrochemical hydrogen production: Using cobalt phosphide nanoarray as a bifunctional catalyst. (19th October 2017)

• Record Type: Journal Article
• Authors: Hao, Shuai; Yang, Libin; Liu, Danni; Du, Gu; Yang, Yingchun; Asiri, Abdullah M.; Sun, Xuping
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 42(2017)
• Page Start: 26289
• Page End: 26295
• Publication Date: 2017-10-19
• Subjects: Cobalt phosphide nanoarray -- Sodium sulfide electro-oxidation -- Hydrogen production -- Bifunctional catalyst; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.05.217
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Water splitting is an important process to produce hydrogen fuels and oxygen evolution reaction (OER), the anodic half reaction, is identified as the bottleneck for its kinetic and energetic complexity in improving the overall efficiency. In this communication, we report that cobalt phosphide nanoarray in situ grown on Ti mesh (CoP NA/TM) behaves as a durable robust non-noble-metal electrocatalyst for sodium sulfide (Na2 S) oxidation with the need of potential of 1.31 V to drive 20 mA cm −2 in 1.0 M KOH with 50 mM Na2 S. The high hydrogen-evolving activity for CoP NA/TM enables it as a bifunctional catalyst electrode for energy-efficient electrochemical hydrogen generation by replacing OER with Na2 S oxidation reaction. The CoP NA/TM||CoP NA/TM couple needs a cell voltage of 1.49 V to drive 15 mA cm −2, 210 mV less than of pure water splitting, with strong long-term electrochemical durability and 100% Faradic efficiency for hydrogen evolution. Highlights: CoP NA/TM shows high catalytic activity toward Na2 S oxidation. The catalyst couple needs 1.49 V to drive 15 mA cm −2 by replacing OER with SSOR. The catalyst couple shows long-term durability and 100% Faradic efficiency.