Designing electrocatalysts: from first principles to efficient green energy applications

Abstract

Many industrially significant reactions nowadays require a catalyst to be economically viable. Therefore the design of active, stable and affordable materials is among the most important areas in the chemical science. A possible approach for fine tuning of the catalysts' properties is through the insertion of foreign elements into the crystalline lattice of an active material. This project aims to design new cost-effective electrocatalysts for the hydrogen evolution reaction (HER). This is one of the key processes in green energy conversion and storage, and activity and stability of a catalysis strongly depend on the working conditions, such as pH. The main strategy is to investigate the effect of transition metal dopants on catalytic activity of molybdenum-based materials through the use of commonly accepted activity descriptors. Studies will be performed both theoretically, by using Density Functional Theory and experimentally by determining the electrocatalytic activity and stability of selected materials, under proper HER working conditions. Main topics of study to be addressed here are: (1) to determine active sites for hydrogen evolution on molybdenum-based catalysts, such as Mo2C and/or MoSe2; (2) to identify the changes on electronic properties of parent and dopant materials upon metal insertion, paying special attention to the commonly accepted intrinsic descriptors for HER activity, such as work function of the surface, d-band center and/or atomic H adsorption energy; (3) to estimate from a theoretical approach the effect of pH on HER activity and identify possible suitable candidate catalysts for HER; (4) to synthesize identified molybdenum-based composites and characterize them by using several techniques such as X-ray diffraction, transmission electron microscopy, in situ X-ray absorption spectroscopy and cyclic voltammetry; and, finally (5) to evaluate the electrocatalytic HER activity and stability of prepared materials in a wide range of pHs (AU)