Carbon dioxide conversion into useful products has been gaining considerable attention as a global‐warming‐mitigation technique. The electrochemical conversion of CO₂ into high‐value chemicals involves the utilization of electrical energy in the presence of an effective catalyst. The process products depend on the number of transferred electrons during the reaction and the characteristics of the electrode. Recently, electrodes coupled with active catalysts have been used to convert CO₂ into valuable products including formic acid, hydrocarbons, and syngas. This review offers an overview of the recent literature on the electrochemical conversion of CO₂ to valuable products, with an emphasis on the production of formate/formic acid. In addition, it compares the main features of electrochemical conversion to other techniques and summarizes their key advantages. It also provides future perspective for research and development, such as the need for novel and selective catalysts to obtain high conversion and product yield with low energy consumption.

The increasing concentration of carbon dioxide (CO₂) in the atmosphere has compelled researchers and policymakers to seek urgent solutions to address the current global climate change challenges.

Achieving net-zero emissions by 2050 will require tackling both energy-related and non-energy-related GHG emissions, which can be achieved through the transition to a circular economy (CE). The focus of climate change crisis reversal has been on the energy-related continuum over the years through promoting renewable energy uptake and efficiency in energy use. Clean energy transition and efficiency gains in energy use alone will not be sufficient to achieve net-zero emissions in 2050 without paying attention to non-energy-related CO₂ emissions. This study systematically reviews the CE literature across different themes, sectors, approaches, and tools to identify accelerators in transitioning to a CE. The study aims to understand and explore how technology, finance, ecosystem, and behavioral studies in the CE paradigm can be integrated as a decision-making tool for CE transition. The material analysis was carried out by identifying the main characteristics of the literature on CE implementation in the agriculture, industry, energy, water, and tourism sectors. Results of the literature survey are synthesized to engender clarity in the literature and identify research gaps to inform future research. Findings show that many studies focused on technology as an accelerator for CE transition, and more studies are needed regarding the CE ecosystem, financing, and behavioral aspects. Also, results show that CE principles are applied at the micro-, meso-, and macro- (national, regional, and global) levels across sectors with the dominance of the industrial sector. The agriculture, water, and energy sectors are at the initial stages of implementation. Additionally, the use of carbon capture and utilization or storage, conceptualized as a circular carbon economy, needs attention in tackling CE implementation in the energy sector, especially in hydrocarbon-endowed economies. The major implication of these findings is that for CE to contribute to accelerated net-zero emission by 2050, coordinated policies should be promoted to influence the amount of financing available to innovative circular businesses and technologies within an ecosystem that engenders behavioral change towards circularity.

Considering the global scientific and industrial effort to utilize ammonia as an alternative to natural gas combustion to run power plants, it is crucial to objectively assess the literature before adjusting or proposing new and advancing techniques in ammonia plants while considering a variety of factors. As a result, this paper assesses the global effort to improve existing ammonia plants and identifies progress by evaluating the currently available dataset to identify knowledge gaps and highlight aspects that have yet to be addressed. Based on the literature reviewed in this study, it was found that the majority of the efforts to advance ammonia plants mainly focus on reducing energy consumption, implementing alternative methods to extract the necessary hydrogen and nitrogen in the process, and changing the cycle arrangement and operating conditions to make the industrial plants more compact. However, regarding carbon reduction in the ammonia production process, it is clear that the effort is less significant when compared to the global scientific and industrial progress in other areas.

The effects of a hydrogen bond acceptor and hydrogen bond donor on carbon dioxide absorption via natural deep eutectic solvents were studied in this work. Naturally occurring non-toxic deep eutectic solvent constituents were considered; choline chloride, b-alanine, and betaine were selected as hydrogen bond acceptors; lactic acid, malic acid, and fructose were selected as hydrogen bond donors. Experimental gas absorption data were collected via experimental methods that uses gravimetric principles. Carbon dioxide capture data for an isolated hydrogen bond donor and hydrogen bond acceptor, as well as natural deep eutectic solvents, were collected. In addition to experimental data, a theoretical study using Density Functional Theory was carried out to analyze the properties of these fluids from the nanoscopic viewpoint and their relationship with the macroscopic behavior of the system, and its ability for carbon dioxide absorption. The combined experimental and theoretical reported approach work leads to valuable discussions on what is the effect of each hydrogen bond donor or acceptor, as well as how they influence the strength and stability of the carbon dioxide absorption in deep eutectic solvents. Theoretical calculations explained the experimental findings, and combined results showed the superiority of the hydrogen bond acceptor role in the gas absorption process, with deep eutectic solvents. Specifically, the cases in which choline chloride was used as hydrogen bond acceptor showed the highest absorption performance. Furthermore, it was observed that when malic acid was used as a hydrogen bond donor, it led to low carbon dioxide solubility performance in comparison to other studied deep eutectic solvents. The cases in which lactic acid was used as a hydrogen bond donor showed great absorption performance. In light of this work, more targeted, specific, deep eutectic solvents can be designed for effective and alternative carbon dioxide capture and management.