CO2 reduction for fuels and chemicals production

Electrochemical CO2 reduction upgrades abundant molecules, CO2 and water, into a variety of carbon-based fuels and chemicals (e.g. ethanol and ethylene). It is a promising technology for both CO2 mitigation and long-term energy storage when combined with intermittent renewable electricity.  So far, CO2 reduction is still a challenging surface reaction as it involves multiple bonds breaking (C-O) and formation (C-C and C-H), and transfer of multiple electron-proton pairs (up to 8  electron-proton pairs per carbon atom).

To control this reaction, our research aim to establish in-depth understandings of the surface chemistry, including identifying the active sites and reaction intermediates, establishing the structure-performance correlations, leveraging the micro-environment effects and others. The successes in controlling the selectivity and activity of CO2 reduction will further motivate the design and fabrication of reactors (e.g. vapor-feed) that achieve high reaction rates and overall conversions for larger-scale applications.

Water splitting for H2 production and its reverse reaction

Electrolytic production of H2 and its widely usage is one of the key enablers of sustainable energy and chemical industry system. Despite the vast interest in water electrolysis technologies, the state-of-the-art materials designed for splitting water to produce hydrogen still remain in noble metals and metal oxides. Platinum is so far the best catalyst candidate for the cathode reaction (hydrogen evolution reaction, HER) in different water electrolyzer, due to its superior activity under almost all applied conditions. Iridium oxide is generally used for the anode reaction (oxygen evolution reaction, OER) in proton exchange membrane (PEM) electrolyzers, due to its ability of surviving in acidic reaction environment in spite of its unsatisfactory activity for OER.

We study the surface structures and properties of catalysts that govern HER/OER activity and stability under necessary reaction conditions, and further establish effective catalyst and system design principles. Obtained knowledge and insights will be applicable to the reverse water splitting reaction, which is the key of fuel cell technologies. In this reaction, Platinum based materials are again the champion catalysts for both the anode reaction (hydrogen oxidation reaction, HOR) and cathode reaction (oxygen reduction reaction, ORR). The usage of Platinum at the ORR side is particularly high.

Our goal is to advance the understanding of the ORR process occurring on various surfaces and to uncover fundamental insights that can rationally guide the design of new cost-effective catalyst materials.

Electrochemical organic transformations

Modern organic synthesis has made a great progress in increasing atom efficiency, reducing reaction steps and moving towards the development of green catalytic systems that could be powered by renewable energy. However, in most of redox reactions in organic synthesis, strong reductants and oxidants are still required, making these processes undesirable from an economic and environmental point of view. Therefore, it is of great interest to drive redox reactions electrochemically by generating reducing and oxidizing agents in situ from only water and renewable electrons.

By studying the thermodynamics and kinetics of activating full range of function groups in electrochemical systems, we aim to understand the effects of the electrode structure, substrate structure and micro-environments on the reaction activity and selectivity (regioselectivity and stereoselectivity). The success on electron-driven activation of these function groups will enable us to target on a large range of organic and biomass biomass conversion through sustainable processes.