Catalyst Stability in Aqueous Electrochemistry

Abstract

The main challenges in catalysis are high activity, selectivity, cost efficiency, and stability. In industrial processes, stability in particular is of pressing concern, and its importance has become more and more acknowledged in academia. At the same time, the need for alternatives to replace fossil raw materials is omnipresent, and the electrification of synthetic processes is picking up in speed. New processes are being developed and novel materials are being tested, while assessing the stability of emerging catalysts can be time-consuming and frustrating but, at the same time, highly important. This problem is exacerbated by a clear lack of realistic stability measurements of new catalysts and an understanding of the key driving forces for the specific degradation pathway. In this perspective, deactivation processes in aqueous electrochemistry are selectively discussed and mitigation strategies are presented. A special focus is placed on the intrinsic material properties that react to the surrounding environment. The applied conditions not only predefine the product spectrum and activity of the catalytic material but also strongly influence the catalyst’s stability. We review various concepts to increase the stability, for instance, by tailoring the coordination environment around the active center, and highlight the importance of the support material. The presented concepts together with stability descriptors serve as important guidelines toward stable and sustainable catalyst systems.

Structural Transformation and Degradation of Cu Nanocatalysts during Electrochemical CO2 Reduction Reaction

“…We collected in situ XANES spectra as a function of applied potentials in CO 2and Ar-purged electrolytes (Supplementary Figs. [20][21][22]. Repeated XANES spectra were collected until no further changes were observed, and the rst derivatives of the XANES spectra were used to evaluate the oxidation states of Cu NPs.…”

“…In addition to these chemical processes, other degradation pathways including catalyst detachment from conductive supports and support deformation are expected to occur simultaneously and intertwine with each other. 21 Therefore, the growing importance of stable Cu electrocatalysts demands a fundamental understanding of key driving forces and kinetics of speci c degradation mechanisms during the CO 2 RR.…”

Navigating the unknown with AI: multiobjective Bayesian optimization of non-noble acidic OER catalysts

“…While many HT campaigns focus solely on the catalyst activity, screening the stability is crucial to adequately identify high-performing catalysts. 17,18 However, the evaluation becomes more time and resource-intensive with each additional property being assessed. 19 Combining thorough testing of each sample with a grid-search-based strategy for vast search spaces prolongs the total measurement time, losing the essence of HT screening.…”

Catalyst Stability Considerations for Electrochemical Energy Conversion with Non-Noble Metals: Do We Measure on What We Synthesized?

“…Thereby, catalyst stability is of central importance to properly address both challenges. 3 While catalyst degradation phenomena are widely studied in the case of noble metals in polymer electrolyte membrane fuel cells (PEMFCs) and electrolyzers, catalyst stability is often neglected in the search for earth-abundant, low-cost catalyst alternatives. 4−6 However, especially when non-noble metals are studied, the stability of the catalyst during the various stages from synthesis to postreaction characterization is of utmost importance to unambiguously evaluate the intrinsic properties of the material.…”

“…The generation of green hydrogen is so far the most developed technology, but also other processes such as electrochemical conversion of carbon dioxide and generation of hydrogen peroxide are growing in scale. , With increasing industrialization of these processes, the focus of research is shifting from finding active catalysts as proof-of-concept to optimization of the technology with respect to lifetime and cost. Thereby, catalyst stability is of central importance to properly address both challenges . While catalyst degradation phenomena are widely studied in the case of noble metals in polymer electrolyte membrane fuel cells (PEMFCs) and electrolyzers, catalyst stability is often neglected in the search for earth-abundant, low-cost catalyst alternatives. − However, especially when non-noble metals are studied, the stability of the catalyst during the various stages from synthesis to post-reaction characterization is of utmost importance to unambiguously evaluate the intrinsic properties of the material.…”