Advances in Operando Spectroscopy and Microscopy of Catalysts to Make Chemicals from CO2 and Plastic Waste

As we enter the era of catalytic activation of small molecules, such as CO2, N2 and H2O, to realize the so-called refinery of the future one of the main questions to answer for scientists involve the coupling of carbon fragments, originating from CO2. The goal is to manufacture increasingly complex carbon-containing molecules from CO2 - or the related molecule CO - instead of making them from crude oil fractions. This requires a profound knowledge of the physicochemical processes taking place at the catalytic surface of both thermo- and electrocatalytic activation processes of CO2. This is the topic of the lecture, in which I will discuss the latest progress made in our group in understanding CO2 activation over nickel and cobalt (thermocatalytic conversion) as well as copper (electrocatalytic conversion), and the subsequent conversion processes of the reaction products to make long-chain hydrocarbons, methanol and aromatics, thereby making use of combination catalyst materials and reaction processes. Special emphasis is on the use of advanced operando spectroscopy and microscopy methods to elucidate both reaction and deactivation mechanisms. Examples include vibrational spectroscopy (infrared and Raman), X-ray methods (X-ray absorption and diffraction), electronic spectroscopy (UV-Vis, fluorescence and luminescence) as well as electron microscopy. I will discuss the design of operando cells, the strength and weaknesses of the different analytical methods, and the required data analysis tools, futher corroborated by theoretical calculations. The last part of the talk will be focused on the conversion of alternative resources, namely plastic waste, thereby illustrating the issue of mass transfer processes, as well as the role of active sites embedded at the outer surface of solid catalysts, to ensure for example pre-cracking of these large hydrocarbon molecules.

Speaker:  Bert Weckhuysen, Utrecht University

This is lecture 2 of 2.  The first was held on February 21.