Protonic Ceramic Electrochemical Cells for Synthesizing Sustainable Chemicals and Fuels

Abstract

Protonic ceramic electrochemical cells (PCECs) have been intensively studied as the technology that can be employed for power generation, energy storage, and sustainable chemical synthesis. Recently, there have been substantial advances in electrolyte and electrode materials for improving the performance of protonic ceramic fuel cells and protonic ceramic electrolyzers. However, the electrocatalytic materials development for synthesizing chemicals in PCECs has gained less attention, and there is a lack of systematic and fundamental understanding of the PCEC reactor design, reaction mechanisms, and electrode materials. This review comprehensively summarizes and critically evaluates the most up‐to‐date progress in employing PCECs to synthesize a wide range of chemicals, including ammonia, carbon monoxide, methane, light olefins, and aromatics. Factors that impact the conversion, selectivity, product yield, and energy efficiencies are discussed to provide new insights into designing electrochemical cells, developing electrode materials, and achieving economically viable chemical synthesis. The primary challenges associated with producing chemicals in PCECs are highlighted. Approaches to tackle these challenges are then offered, with a particular focus on deliberately designing electrode materials, aiming to achieve practically valuable product yield and energy efficiency. Finally, perspectives on the future development of PCECs for synthesizing sustainable chemicals are provided.

Tuning the product selectivity of CO2/H2O co-electrolysis using CeO2-modified proton-conducting electrolysis cells

“…Although the temperature used in this work (550 °C) was still relatively high for the methanation reaction reported in the literature, 32 we demonstrated surface engineering as an effective strategy to promote the co-electrolysis of CO 2 and H 2 O to generate CH 4 using PCECs. It is worth noting that since the CO 2 hydrogenation reaction to produce CH 4 is an exothermic reaction, 33 a higher function temperature is not beneficial for the production of CH 4 . However, it can facilitate the migration of protons towards the fuel electrode surface, which promotes the hydrogenation of CO 2 because the protons driven by the applied voltage actively participates in the CO 2 hydrogenation reaction.…”

“…Although the temperature used in this work (550 1C) was still relatively high for the methanation reaction reported in the literature, 32 we demonstrated surface engineering as an effective strategy to promote the co-electrolysis of CO 2 and H 2 O to generate CH 4 using PCECs. It is worth noting that since the CO 2 hydrogenation reaction to produce CH 4 is an exothermic reaction, 33 a higher function temperature is not beneficial for the production…”

A review of progress in proton ceramic electrochemical cells: material and structural design, coupled with value-added chemical production

“…While some reports compare the current density at a thermally neutral or identical voltage, 410,411 there remains a necessity to present and distinguish results such as the CO 2 conversion rate, product selectivity, product yield, and other detailed parameters. 54,371,412 Considering the products as containing only CO and CH 4 , critical parameters such as the CO 2 conversion rate, selectivity of products (CO/CH 4 ), yield of products (CO/ CH 4 ), and Faraday efficiency could be calculated employing the following equations: The challenges associated with the kinetics of CO 2 conversion reaction stem from the chemical inertness and linear stability of the molecule. These factors, coupled with the presence of competitive HER, could result in the observed linear increase in H 2 production with increasing current density, instead of an anticipated increase in carbon-derived products.…”

Novel co-doped protonic conductors BaLa1.9Sr0.1In1.95M0.05O6.925 with layered perovskite structure

“…Electrochemical devices such as proton-conducting fuel cells [1][2][3] and electrolyzers [4,5] are in dire need of highly efficient materials with targeted properties including proton conductivity [6][7][8]. Active development and implementation of these devices as a part of the "hydrogen energy in everyday life" strategy should ensure sustainable environmental development [9][10][11][12][13][14][15][16].…”