Advancing the Electrochemistry of Gas‐Involved Reactions through Theoretical Calculations and Simulations from Microscopic to Macroscopic

Abstract

Nowadays, gas‐involved electrochemical reactions, such as carbon dioxide reduction reaction (CO2RR), nitrogen reduction reaction (NRR), and hydrogen evolution reaction (HER), have gradually become viable solutions to the global environmental pollution and energy crisis. However, their further development is inseparable from the in‐depth understanding of reaction mechanisms, which are incredibly complicated and cannot be satisfied by experiments alone. In this context, theoretical calculations and simulations are of great significance in establishing composition–structure–activity relationships, providing priceless mechanistic discernment and predicting prospective electrocatalysts and systems. Among them, density functional theory (DFT), molecular dynamics (MD) simulations, and finite element simulation (FES) are emerging as three mature theoretical tools. This paper presents a review of the basic principles and research progress of DFT, MD, and FES to deepen the understanding of CO2RR, NRR, and HER. Some remarkable work around theoretical calculations and simulations are highlighted, including the utilization of DFT to investigate the intrinsic properties of catalysts and MD or FES to restore the whole reaction systems from different temporal and spatial scales. Eventually, to sum up, forward‐looking insights and perspectives on the future optimizations and application modes of the three computational techniques to compensate for their shortcomings and limitations are presented.

In Situ Construction of Metal–Organic Frameworks as Smart Channels for the Effective Electrocatalytic Reduction of Nitrate at Ultralow Concentrations to Ammonia

“…It can be clearly observed that the conversion rate of nitrate (97.6%), ammonium generation selectivity (95.2%), and Faradaic efficiency (91.4%) of UiO-CuZn are much higher than those of pristine UiO (46.4, 24.2, and 35.8%), CuZn (32.4, 35.2, and 30.6%), and UiO + CuZn electrocatalysts (36.9, 31.3, and 42.6%) (Figure e), respectively, demonstrating the conspicuous NO 3 RR performance over the CuZn-incorporated UiO electrocatalyst. The Faradaic efficiency of ammonia generation is much higher than the reported N 2 reduction to ammonia because of the extremely high kinetic energy barriers that have to be overcome, ,, while the conversion rate of nitrate and the selectivity of ammonia are superior to the state-of-the-art nitrate reduction systems in similar environments (Figure f, detailed comparison in Table S3). ,− Compared with most nitrate reduction electrocatalysts reported, the as-prepared electrocatalysts can not only completely remove nitrate pollutants from aqueous solutions but also selectively convert nitrate to high-value ammonia.…”

“…It is increasingly critical to remove nitrates from water and subsequently convert them into harmless or, better yet, high-value-added products. Electrocatalytic reduction driven by renewable electricity has emerged as an effective strategy to manage nitrates in water, during which nitrogen oxyanions, hydroxylamine, dinitrogen, and ammonia are the main products. , Particularly, ammonia (NH 3 ) is the cornerstone for agricultural fertilizer and industrial chemical manufacture and also an important energy storage medium and carbon-free energy carrier. − Industrial-scale NH 3 production heavily relies on the energy-intensive Haber–Bosch process, which requires harsh operating conditions (including high temperature and pressure) and consumes significant amounts of energy. − As an alternative, the electrocatalytic dinitrogen (N 2 ) reduction reaction (NRR) in water under ambient conditions has attracted increasing attention for its safety, low cost, and environmental friendliness. , However, the reaction rate and selectivity are hampered by the extremely stable NN triple bond (941 kJ mol –1 ) in nonpolar N 2 gas. , Ideally, NO 3 – is considered as an attractive nitrogen source because of the relatively low dissociation energy of the NO bond (204 kJ mol –1 ). Simultaneously, it is one of the most widespread water pollutants in the world, which seriously endangers human health and the ecological environment .…”

Deciphering Electrolyte Selection for Electrochemical Reduction of Carbon Dioxide and Nitrogen to High‐Value‐Added Chemicals

“…For a long time, researches about electrocatalytic CO 2 reduction reaction (CO 2 RR) and electrocatalytic N 2 reduction reaction (NRR) have been mainly focused on the exploration of electrocatalysts since they improve the reaction rate, efficiency, and selectivity toward desired products. [16][17][18] A large number of publications show that numerous efforts have been made to design and construct the active sites on the surface of electrocatalysts to enhance the performance of CO 2 RR and NRR, including the regulation of crystal facets, [19][20][21] surface morphology, [22][23][24][25] particle size, [26][27][28] oxidation state, [29,30] and heteroatom doping. [31][32][33] Although these regulation methods have got some obvious advance, they cannot overcome the fatal flaws of overall electrocatalytic processes, including the low solubility of CO 2 and N 2 in electrolyte, and the competitive hydrogen evolution reaction (HER).…”

Turning Waste into Wealth: Sustainable Production of High-Value-Added Chemicals from Catalytic Coupling of Carbon Dioxide and Nitrogenous Small Molecules

“…An alternative to storage is the purposeful utilization of CO 2 as a feedstock for the synthesis of various value-added chemicals, known as CO 2 capture and utilization (CCU), which may provide more economic benefits for a carbon-neutral economy. , CCU is expected to utilize renewable energy sources and abundant feedstocks to achieve sustainable chemistry processes and stimulate the development of routes and concepts to go beyond fossil fuels. , Although various single-carbon (C 1 ) and multi-carbon (C 2+ ) products can be selectively produced with greatly reduced carbon footprint to date, − the scope of CCU is not, however, limited to C/H/O-based reactants, and the synthesis of valuable chemicals beyond simple carbon species can also be realized. For instance, the incorporation of the element nitrogen could achieve C–N bond formation and yield organonitrogen compounds.…”