1) Wider research context
The design of novel materials capable of converting CO2 into value-added fuels and chemicals can not only reduce the emissions of CO2 in the atmosphere but also allow for a transition from linear to cyclic carbon economy. Among promising catalytic materials, MXenes, a recently discovered family of two-dimensional (2D) transition metal carbides or nitrides have garnered increasing attention for nearly a decade by virtue of their versatile composition, structure, stability under conditions of interest in heterogeneous catalysis, and numerous appealing properties. Their chemical diversity and tailorability, allowing for the systematic variations of both the intrinsic compositions and surface terminations, have allowed MXenes to stand out over other 2D materials.
This project envisions understanding how MXenes can be tailored to enable and optimise their catalytic activity for converting CO2 to value-added fuels and chemicals, including methanol, DME, alkanes, lower olefins, and higher alcohols. We will systematically screen by means of Density Functional Theory (DFT) calculations and Kinetic Monte Carlo (KMC) a large set of MXenes-based catalysts and consider their suitability for the CO2 valorisation reactions as a function of their surface chemistries. This project will be conducted in close collaboration with experimentalists, who will test the chosen candidates and provide valuable data and feedback throughout the project.
2) Objectives
- unveil the rate-determining and selectivity-determining steps for CO2 hydrogenation,
- understand how the energy barriers of the critical elementary steps and the relative stabilities between adsorbed species can be modulated by changing the nature of the dopant atoms
- identify the most promising MXene-based candidates for each type of product
- test the catalytic performance of the most promising candidates experimentally
- use the knowledge learned towards the rational design of novel carbide catalysts for CO2 hydrogenation to valuable products.
3) Methods
DFT calculations will be performed using PBE exchange-correlation functional as implemented in VASP code, including dispersion interactions. The transition states will be computed using machine-learning accelerated nudged elastic band calculations. KMC simulations will be performed using the Zacros package.
4) Level of originality
This project lies at the interface between materials science, computational chemistry, catalysis, and chemical reaction engineering, and combines two prominent and exciting research fields: CO2 valorisation and functionalised MXenes. CO2 hydrogenation to C2+ products is currently receiving a lot of attention, but no attempts to address it on MXenes have been made.
5) Primary researchers involved
Principal investigator: Dr. Hector Prats Garcia
Mentor: Asst. Prof. Aleix Comas Vives (TU Wien)
International Cooperation Partner: Dr. Alexey Fedorov (ETH Zurich)
