Future Challenges in Heterogeneous Catalysis: Understanding Catalysts under Dynamic Reaction Conditions

Abstract

In the future, (electro‐)chemical catalysts will have to be more tolerant towards a varying supply of energy and raw materials. This is mainly due to the fluctuating nature of renewable energies. For example, power‐to‐chemical processes require a shift from steady‐state operation towards operation under dynamic reaction conditions. This brings along a number of demands for the design of both catalysts and reactors, because it is well‐known that the structure of catalysts is very dynamic. However, in‐depth studies of catalysts and catalytic reactors under such transient conditions have only started recently. This requires studies and advances in the fields of 1) operando spectroscopy including time‐resolved methods, 2) theory with predictive quality, 3) kinetic modelling, 4) design of catalysts by appropriate preparation concepts, and 5) novel/modular reactor designs. An intensive exchange between these scientific disciplines will enable a substantial gain of fundamental knowledge which is urgently required. This concept article highlights recent developments, challenges, and future directions for understanding catalysts under dynamic reaction conditions.

Multi-Scale Simulation of Heterogeneous Surface Film Growth Mechanisms in Lithium-Ion Batteries

“…EC (C 3 H 4 O 3 ) is reported to break down by consuming an electron through the breakage of one of the C-O bonds next to the C 2 H 4 group to form C 3 12 Standard state chemical potentials and remaining reaction energies are chosen based on the data where applicable and otherwise chosen in the adequate order of magnitude. A quantitative computational determination of all parameters for this reaction mechanism via DFT simulations is yet not possible 9 and remains the subject of future studies. Additional parameters as applied in those simulations are summarized in Table IV. As the parameters and mechanisms are not fully available in literature, the results should be considered as a first qualitative insight into the formation process and an assessment of the multiscale nature of SEI growth, and as a demonstration of the multiscale model as a way to evaluate hypothesized mechanisms.…”

“…Indeed, Kalz et al 9 pointed out the general need for a deeper analysis and advanced modeling of changes of reactive surfaces. New modeling methods need to be explored, which allow application to lithium-ion batteries for a detailed simulation of heterogeneous growth mechanisms while considering the experimentally found impact of macroscopic properties.…”

“…3,4 Although SEI film formation has been studied for decades using experimental and simulation-based methods, the exact mechanism of chemical and electrochemical reactions and the growth of the solid film is not understood. Indeed, Kalz et al 9 pointed out the general need for a deeper analysis and advanced modeling of changes of reactive surfaces. New modeling methods need to be explored, which allow application to lithium-ion batteries for a detailed simulation of heterogeneous growth mechanisms while considering the experimentally found impact of macroscopic properties.…”

Surface Oxidation of Supported Ni Particles and Its Impact on the Catalytic Performance during Dynamically Operated Methanation of CO2

“…Both steps need to withstand fluctuations in supplied electricity from wind and solar plants, which occur temporarily and fluctuate on a time scale of seconds to days. When using a small or even no H 2 reservoir, these fluctuations are transferred to the catalytic reactor imposing a varying supply of H 2 used to hydrogenate CO 2 [5][6][7][8].…”

“…The dynamics in the methanation originating from fast load changes of the H 2 supply are a key challenge [5] and are therefore the subject of present research. The catalytic methanation of CO 2 is well-known, and numerous articles can be found in the literature reporting CO 2 conversion and CH 4 selectivity under optimized and steady state conditions [9,10].…”