(Invited) Transition Metal and Carbon Composites for Hydrogen Evolution Reaction at Universal Phs

Wednesday, 31 May 2017: 15:30
Grand Salon A - Section 3 (Hilton New Orleans Riverside)
L. Zhang and M. Shao (The Hong Kong University of Science and Technology)
Owing to the climate change and shortage of fossil fuels, renewable energy sources such as solar and wind have become more and more attractive. However, these energies are intermittent and difficult to control. Water splitting provides hope to store these renewable energies in the form of hydrogen through a sustainable method. Up to now, the most popular cathodic electrocatalysts used in commercial solid polymer electrolyte (SPE) electrolyzers are still Pt-based materials that are highly scarce and costly. Therefore, one of the main challenges to generate hydrogen is to develop efficient and cost-effective catalysts toward hydrogen evolution reaction (HER) to replace Pt.

Non-precious metal and nitrogen co-doped carbon-based materials synthesized via different methods are explored for HER at universal pHs. It was found that the HER activity was highly dependent on the preparation method, type of transition metal/non-metal doping and compound formed. The lowest overpotential at 10 mA cm-2 was 190 mV in a 0.5 M H2SO4 solution at a catalyst loading of 0.255 mg cm-2 for Fe3C-C based composite. Density functional theory (DFT) calculations were applied to calculate the hydrogen binding energy and reaction barriers on various possible active sites. This talk will summarize recent systematic work on carbon-based composite materials for HER in my group.