(6g) Rational Catalyst Design for Renewable Energy Technologies

Authors: 
Siahrostami, S., Stanford University
Research Interests:

Today, there is an extensive interest in replacing fossil fuels to supply mankind energy needs sustainably on a long-term basis. In recent years several renewable energy technologies have been developed such as fuel cells, metal-air batteries and electrolyzers. There are, however, severe shortcomings of the present technologies, which need to be overcome to make these processes more economically attractive. One of the most important problems is the lack of active, selective and inexpensive catalysts for these processes. My research focuses on designing cost-effective and efficient heterogeneous catalysts for the application in energy conversion devices such as fuel cells, batteries, and chemical synthesis processes. The design of catalysts will be guided by computational modeling in particular DFT with an emphasis on understanding the electronic structure of the catalyst and adsorbed surface species. In particular I am interested in 1) developing efficient catalysts for oxygen reduction reaction (ORR) in fuel cells and oxygen evolution reaction (OER) in metal-air batteries and water electrolyzers. 2) Additionally I am interested in synthesizing fuels using biomass, methane oxidation and electrochemical conversion of CO2to hydrocarbons.

Recent theoretical understandings indicate that there are universal correlations (scaling relations) between surface bond energies of different adsorbed species that bind to the surface through similar atom for specific reaction.1,2 These correlations pose limitations on many of the known catalysts for reactions such as ORR, OER, CO2 reduction and N2 reduction reactions.3 Therefore, catalyst design requires development of new, effective and non-precious catalysts with active site motifs, which do not follow the similar correlation. My work utilizes theoretical tools in particular DFT to model two-dimensional materials with different modification strategies including doping and defect design to describe the surface reactions. These strategies have not been explored so far. I seek to find a breakthrough for scaling relations and my goal is to discover novel catalysts for the following applications: 1) improving the efficiency of the devices that are related to sustainable energy applications, i.e. fuel cells4, electrolyzers5, and metal-air batteries6, and 2) to discover/design new, effective and non-precious catalysts for ORR, OER, and CO2 reduction reaction, fuel synthesis from biomass, and methane oxidation.

Another important issue facing humanity is related to the potable water. Millions of people in the developing world are lacking access to drinking water due to its contamination with urban, industrial and agricultural waste. These pollutants can in principle be removed by their total oxidation by hydrogen peroxide (H2O2) as a strong oxidizing agent without leaving any residues behind. Production and transportation of H2O2 to the developing world, however, is challenging due to high costs and safety issues, making this potentially game-changing chemical largely inaccessible to the massive number of people who need it the most. My research combines the expertise from fundamental understanding of the reaction and DFT with versatile synthetic methods, electrochemical evaluation and catalyst characterization to develop an electrochemical route by designing an efficient and cost effective electrocatalyst for selectively reducing O2 to H2O2 to enable continuous, small-scale and decentralized production of H2O2.7,8

 

References:

(1) Viswanathan, V.; Hansen, H. A.; Rossmeisl, J.; Nørskov, J. K. ACS Catal. 2012, 2(8), 1654â??1660.

(2) Man, I. C.; Su, H.-Y.; Calle-Vallejo, F.; Hansen, H. A.; Martínez, J. I.; Inoglu, N. G.; Kitchin, J.; Jaramillo, T. F.; Nørskov, J. K.; Rossmeisl, J. ChemCatChem 2011, 3(7), 1159â??1165.

(3) Vojvodic, A.; Nørskov, J. K. Natl. Sci. Rev. 2015, 2(2), 140â??149.

(4) Siahrostami, S.; Björketun, M. E.; Strasser, P.; Greeley, J.; Rossmeisl, J. Phys. Chem. Chem. Phys. 2013, 15(23), 9326â??9334.

(5) Siahrostami, S.; Vojvodic, A. J. Phys. Chem. C 2015, 119(2), 1032â??1037.

(6) Siahrostami, S.; TripkoviÄ?, V.; Lundgaard, K. T.; Jensen, K. E.; Hansen, H. a; Hummelshøj, J. S.; Mýrdal, J. S. G.; Vegge, T.; Nørskov, J. K.; Rossmeisl, J. Phys. Chem. Chem. Phys. 2013, 15(17), 6416â??6421.

(7) Siahrostami, S.; Verdaguer-Casadevall, A.; Karamad, M.; Deiana, D.; Malacrida, P.; Wickman, B.; Escudero-Escribano, M.; Paoli, E. a; Frydendal, R.; Hansen, T. W.; Chorkendorff, I.; Stephens, I. E. L. S.; Stephens, I. E.; Rossmeisl, J. Nat. Mater. 2013, 12(12), 1137â??1143.

(8) Verdaguer-Casadevall, A.; Deiana, D.; Karamad, M.; Siahrostami, S.; Malacrida, P.; Hansen, T. W.; Rossmeisl, J.; Chorkendorff, I.; Stephens, I. E. L. Nano Lett. 2014, 14 (3), 1603â??1608.

Teaching Interests:

I would like to teach courses such as Physical Chemistry, Thermodynamics, Quantum Chemistry, Molecular Spectroscopy and Chemical Kinetics. Moreover, I would be interested in developing and offering new courses in accordance to my area of specialty and research experiences.

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