INPhINIT Incoming Fellowship – Electronic Engineering of 2D materials for Efficient Nitrogen Electrocatalysis
The Computational Electrocatalysis Group (CEG) led by Dr Federico Calle Vallejo uses Density Functional Theory (DFT), atomistic thermodynamics and kinetics, and house-made descriptors to create predictive, structure-sensitive models of electrocatalytic reactions (see a recent review in 10.1039/C9SC02654A). Our models are based on conventional and “generalized” coordination numbers (10.1038/nchem.2226; 10.1126/science.aab3501), “outer” electrons (10.1039/C2SC21601A; 10.1103/PhysRevLett.108.116103) and “electrocatalytic symmetry” (10.1021/acscatal.9b00532).
We are interested in extended surfaces and nanoparticles of transition metals, their alloys and oxides. We model reactions of interest in fuel cells, electrolyzers and pollution control devices such as O2 reduction and evolution, H2 evolution, CO oxidation and reduction, and NOx reduction. CEG actively collaborates with experimenters in The Netherlands, Germany, Singapore, and Madrid.
The Nanoclusters and Nanostructured Materials (2NM) group is headed by Prof. Stefan Bromley and focuses on modelling the properties of low dimensional nanoscale materials (e.g. inorganic nanoclusters – 10.1039/B806400H, organic 2D materials – 10.1038/s41467-017-01977-4). Such materials often display novel size-dependent properties compared to materials at everyday length scales. Employing classical atomistic and quantum chemical methods implemented on powerful supercomputers, we provide detailed and predictive insights into the structural, electronic and chemical properties of nanomaterials. Our main goals are to understand how nanomaterials evolve with respect to their size, and to design viable new materials from nanoscale building blocks. The 2NM group focuses on two classes of materials: i) nanoclusters and nanostructured inorganic materials for energy applications (e.g TiO2, ZnO), ii) nanostructured 2D materials built from organic molecular building blocks for electronics/spintronics.
The colossal imbalance in the nitrogen cycle calls for a portfolio of interconnected solutions (10.1038/461472a). The alarming amounts of nitrates and nitrites in groundwaters can be substantially lowered by means of electrochemical technologies (10.1021/cr8003696). In principle, ammonia can be sustainably produced from nitrate in an electrolyzer powered by solar or wind energy.However, a major problem of this approach is that the two half reactions, namely, nitrate reduction to ammonia and water splitting, suffer from high overpotentials, while nitrate reduction has a tough competition with hydrogen evolution. Thus, stable, active, and selective catalysts based on Earth-abundant elements are currently sought after.Two-dimensional covalent organic radical frameworks (2D-CORFs) were initially proposed by the 2NM group (10.1039/C6SC01412G). Soon afterwards, experimental groups synthesized the first 2D-CORFs and showed their promise in electrocatalysis (10.1002/anie.201801998). However, these new 2D materials remain largely unexplored and the electronic factors modulating their catalytic activities are still unknown.In this interdisciplinary project, the CEG and 2NM groups will join forces to study the electrocatalytic activities for the nitrate reduction of 2D-CORFs in a holistic way. The analysis will consider intrinsic factors such as stretching and compressive strain, and external factors such as support, solvent, and pH effects. We will analyze the different products that can be formed, such as nitrite, NO, N2, NH3, etc., and compare the results to those for hydrogen evolution to understand the trends in activity and selectivity. The goal is to elaborate a comprehensive picture of 2D-CORFs that can guide experimenters toward the synthesis of next-generation electrocatalysts for nitrate reduction. To supplement the study, other materials such as metal-organic frameworks and bimetallic alloys will also be considered.
homepage of Dr Federico Calle-Vallejo
Google scholar profile of Prof. Stefan Bromley
https://scholar.google.com/citations?hl=en&user=GRcDA5cAAAAJ
homepage of Prof. Stefan Bromley