G. Charles Dismukes - Research
Earth-abundant catalysts for the Hydrogen Evolution Reaction (HER)
Hydrogen is a bulk chemical produced on the 107 ton/year scale but could also be a fuel of the future. Today this hydrogen is produced from methane in steam reforming. Switching the hydrogen production to a renewable resource is a challenge, but some electrolyzers produce hydrogen on a commercial scale already from electricity (electrochemically). We are developing hydrogen evolution catalysts for benign neutral conditions in order to reduce hydrogen costs to a level competitive with conventional fuels.
Photoelectrochemical water-splitting (PEC)
Photoelectrochemical cells (PEC) that can split water into hydrogen and oxygen using sunlight are a promising strategy to generate and store clean, renewable energy. However, PEC devices suffer from low stability and efficiency, preventing them to penetrate the market. Our group aims to significantly increase the solar to hydrogen conversion efficiency up to 10% using a tandem configuration, as well as to increase the lifetime of the device. In a tandem device, two semiconductor light absorbers (one for high energy and one for low energy radiation) are combined to utilize most of the solar spectrum. We are also interfacing the photoabsorbers with Rutgers-developed best in class earth-abundant hydrogen and oxygen-evolving catalysts to decrease the required cell potential to drive water splitting.
Earth-abundant catalysts for the Carbon Dioxide Reduction Reaction
We develop selective and robust catalysts that electrochemically convert carbon dioxide (CO2) into sustainable chemical feedstocks and could ultimately be coupled to the recycling of environmental CO2. The catalysts employed are transition metal phosphide and their doped derivatives that form distinct crystalline structure types, enabling selection of chemical reactivity towards desired products including high molecular weight solid polymers. Selecting the catalyst’s elemental composition and crystal structure allows for tuning of the chemical, physical, and electrical properties to achieve the best match with desired product and application.
Perovskite-based oxyhydrides as nitrogen fixation catalysts
Production of ammonia (NH3) continues to increase to satisfy ever-growing global demand. Most industrial production processes are still based on the 100-year-old Haber-Bosch process which requires temperatures of >400 °C and 150-200 atm of pressure to overcome slow dissociation of N2. These harsh reaction conditions have led to NH3 production accounting for 2% of global energy consumption and 1% of global greenhouse gas production. New catalysts that can lower energy requirement and carbon footprint of this process are of interest. Recently, a new class of perovskite-based oxyhydrides (AMO3-xHx; A2MO4-xHx) have been discovered and it has been demonstrated that N3–/H– substitution can be achieved in these compounds by heating under N2 flow. This ability to break the N2 triple bond at ambient pressures makes perovskite oxyhydrides candidates for NH3 production catalysts.
