Industrial Chemistry & Materials最新文献

This work establishes a comprehensive theoretical framework for synthesizing cyclic organic carbonates, crucial for the polymer industry, through the organocatalytic cycloaddition of carbon dioxide (CO₂) to epoxides under mild pressure and temperature conditions. Using advanced computational techniques, the study examines the thermodynamic and kinetic aspects of the reaction, with a particular focus on epoxide substrates featuring diverse substituents. Detailed analysis reveals activation energy barriers and identifies the rate-determining step (rds), offering crucial insights into the molecular processes governing the reaction. An automated data-driven workflow revealed that the buried volume of the epoxide O atoms was among the most influential molecular features affecting reaction barriers. Overall, the findings align with experimental data, offering insights into substrate design for optimized CO₂ utilization. This work calls for a systematic exploration of ascorbic acid-based catalyst modifications to optimize energy barriers and improve overall reaction performance, paving the way for rational catalyst design and predictive catalysis in CO₂ valorization. The computational study is not limited to basic research or ascorbic acid but is applicable to most catalysts capable of carrying out this reaction in the polymer industry.

Keywords: Epoxide; CO₂ activation; Sustainable catalysis; Data-driven workflows; DFT calculations; Predictive catalysis; Cycloaddition.

Designing dual function materials (DFMs) entails an optimisation of CO₂ adsorption and catalytic conversion activity, often requiring a large number of experimental parametric studies screening various types and loadings of adsorbent and catalyst components. In this study, we used a Gaussian process model optimised with Bayesian optimisation (BO) to find the DFM composition leading to the highest methanation activity. We focused on optimising Na (adsorbent) loading in a DFM where Na loading was varied from 2.5–15% by weight. The results from the experimental tests indicated that the sample with the highest Na-loading (15 wt%) possessed the highest CO₂ desorption during CO₂-TPD, however, it was not the best DFM, as it did not show the highest methane production. By testing Bayesian optimisation recommended experiments we identified 7.9 wt% Na as the optimal Na loading, which showed the highest methane production for a cycle (398.6 μmol g_DFM⁻¹) at 400 °C. This forms a case study for how BO can help accelerate materials discovery for DFMs.

Keywords: DFM; ICCC; Methanation; Gaussian process; Bayesian optimisation.

Photothermal catalysis significantly enhances the efficiency of photocatalytic CO₂ reduction, offering a promising strategy for accelerated CO₂ resource utilization. Herein, a series of Cu_xIn_yS photocatalysts were synthesized, exhibiting tunable band gap energy by varying the Cu/In/S atomic ratios for photothermocatalytic CO₂ conversion to C₂H₄. The typical CuInS₂ catalyst demonstrates a more negative conduction band, significantly enhancing the electron reduction ability and facilitating the multi-electron reduction of CO₂ to C₂H₄. Additionally, the abundant sulfur vacancies in CuInS₂ generate additional active sites, enhance charge separation efficiency, and consequently improve catalytic activity. The generation rate of ethylene reaches 45.7 μmol g⁻¹ h⁻¹ with a selectivity of 79.7%. This study provides a new avenue for producing ethylene in photothermal catalysis, as well as highlighting the superiorities of the CuInS₂ catalyst.

Rapid deactivation of CaO-based sorbents remains a major challenge for the calcium looping (CaL) process. Recently, CeO₂, known for its high Tammann temperature and abundant oxygen vacancies, has been extensively investigated for CaO-based sorbents to mitigate performance degradation. In this study, CeO₂-doped CaO-based pellets, prepared in a more industrially relevant form for the first time, were investigated. The incorporation of CeO₂ alleviated the negative impact of pelletization and particle size on performance. CeO₂-doped CaO-based pellets with different particle sizes (106–180, 180–250, 250–355, and 355–500 μm) exhibited nearly identical CO₂ capture performance, closely matching the reactivity of powdery CeO₂-doped CaO-based sorbents. Furthermore, the effects of two steam-based strategies—steam hydration and steam injection—on the reactivity of the CeO₂-doped pellets were explored. Hydration after the sixth calcination significantly enhanced the reactivity of CeO₂-doped CaO-based pellets. Hydration at 650 °C resulted in a conversion of 86.0% at the sixth cycle, surpassing the non-hydrated pellets by 55.4%. In contrast, steam hydration had minimal impact on the performance of undoped CaO-based pellets, indicating that CeO₂ greatly enhanced the improvement from steam hydration. The effect of steam injection was more complex and highly dependent on the steam concentration. Only a moderate steam concentration (10–15%) enhanced the reactivity, leading to higher carbonation conversions. With 10% steam during carbonation, the initial conversion surged to 93.8%, representing a 22.0% improvement over the counterpart without steam.

Keywords: CO₂ capture; Calcium looping (CaL); Stabilizer; Oxygen vacancy; Particle size; Steam.

Effectively controlling the oxidation state of neptunium (Np) is crucial for the separation of Np during the advanced plutonium uranium reduction extraction process. The reduction reactions and kinetics of Np(VI) with salt-free reagents were explored by applying experimental and theoretical studies. This review summarizes the reduction reaction, kinetics, mechanism and electronic structures as well as the potential energy surfaces of Np(VI) to Np(V) using salt-free reagents, such as hydrazine, hydroxylamine, aldehydes, oximes, hydroxamic acids and their derivatives. This review will hopefully serve as a useful resource to inspire further research on the reduction of Np(VI) using salt-free reagents.

Keywords: Reduction kinetics; Reduction mechanism; Np(VI); Salt-free reagents; Theoretical simulation.

Bimetallic layered double hydroxides (LDHs) have attracted substantial attention as oxygen evolution reaction (OER) catalysts. In this work, we provide a facile route to prepare Ti-doped NiCo-LDH/NF electrocatalysts with M–O–Ti (M = Ni, Co) covalent bonds via a rapid immersion method for the OER process. The experiments and density functional theory (DFT) calculations elucidate that the doping of Ti (M–O–Ti) not only exfoliates the NiCo-LDH nanosheets into spheres but also causes lattice distortion to produce more oxygen vacancies, which promotes faster exchange of intermediates and improves the electron transfer efficiency. These superior physical characters endow Ti-NiCo-LDH with an excellent overpotential of 319 mV at a current density of 50 mA cm⁻², which is markedly lower than that of NiCo-LDH (391 mV at 50 mA cm⁻²). Even at a high current density of 100 mA cm⁻², NiCo-LDH displays an overpotential of 429 mV, whereas Ti-NiCo-LDH is capable of achieving an overpotential of 353 mV. Moreover, the water electrolyzer based on the Ti-NiCo-LDH bifunctional catalyst requires a low cell voltage of 1.60 V to achieve a current density of 10 mA cm⁻², and the Ti-NiCo-LDH catalyst has been successfully applied for solar cell-driven water electrolysis and the corresponding voltage is about 1.61 V. This work offers a novel strategy to fabricate high activity NiCo-LDH with rich oxygen vacancies toward the OER process.

Keywords: Ti-doping; NiCo-layered double hydroxide; Oxygen vacancy; Oxygen evolution reaction.

The oxygen evolution reaction (OER) is a critical bottleneck in the commercial evolution of anion exchange membrane water electrolyzers (AEMWEs). As a potential substitute for the scarce and expensive noble metal-based electrocatalysts typically used to improve the OER activity, here amorphous NiFe oxides with varying Ni/Fe ratios were synthesized using a simplistic and cost-effective sol–gel method. After carefully investigating the structural and morphological attributes of the derived electrocatalysts, their OER activities were analyzed by acquiring the half-cell measurements. First, the influence of the electrochemical ink formulation and additives on the activity of the electrocatalyst was studied, followed by elucidating the electrocatalyst loading to configure the working electrode on the rotating disk electrode (RDE). By comparing the activities of different synthesized NiFe oxides, it was observed that Ni_0.75Fe_0.25O delivers the peak performance with a minimum overpotential of ca. 290 mV. Therefore, the aforementioned sample was utilized to configure the anode electrode for a lab-scale AEMWE, achieving 3.7 A cm⁻² at 2 V and 80 °C while demonstrating promising stability trends.

Keywords: NiFe oxide; AEM-WE; Alkaline media; Inorganic oxides; OER; PGM-free electrocatalysts.

The ethanol dehydrogenation (ED) reaction is considered a sustainable pathway for hydrogen production. However, the ED reaction is energy-intensive as it requires high temperatures. Here, we report a layered double hydroxide-derived catalyst composed of CuPt bimetallic nanoparticles for efficient light-driven ED reaction without additional thermal energy input, achieving a hydrogen production rate of 136.9 μmol g⁻¹ s⁻¹. This rate is 1.4 times higher than that achieved at the same temperature in the dark. Experimental results and theoretical simulations suggest that the localized surface plasmon resonance (LSPR) effect of Cu reduces the apparent activation energy of the light-driven ED reaction. The presence of Pt nanoparticles around Cu enhances the LSPR effect, thereby significantly increasing the hydrogen production efficiency.

Keywords: Light-driven; Ethanol dehydrogenation; Hydrogen production; LSPR.

Despite global efforts to reduce the use of fossil fuels, carbon dioxide (CO₂) emissions continue to rise. As the demand for clean energy grows, hydrogen (H₂), which does not emit CO₂ during combustion, is emerging as a promising energy resource. Among the various hydrogen production technologies, water electrolysis is attracting attention as a method for producing green hydrogen without carbon emissions. However, its high reaction overpotentials, due to complex reaction pathways, are a major factor limiting its energy efficiency. To address these issues, chemical-assisted water electrolysis is considered as an innovative alternative. This technology enables hydrogen production at lower voltages. Moreover, it can generate high-value products and remove pollutants, providing both environmental and energy benefits. In this review, we introduce various types of chemical-assisted water electrolysis and discuss the latest advances in catalyst design and reaction mechanisms aimed at reducing applied system voltage. Finally, we address the main challenges and prospects of chemical-assisted water electrolysis.

Keywords: Chemical-assisted water electrolysis; Hybrid water electrolysis; Overpotential; Hydrogen; Electrocatalyst; Value-added product.

Valorization of multiple low value streams including CO₂ emissions and magnesium-hydroxide bearing mine tailings to produce magnesium carbonate through reactive CO₂ capture and mineralization provides a less explored opportunity to manage several gigatons of CO₂ emissions. To resolve the feasibility of converting magnesium hydroxide to magnesium carbonate through reactive CO₂ capture and mineralization, CO₂ capture solvents such as sodium glycinate are harnessed to capture CO₂ and react directly with Mg(OH)₂ to produce hydromagnesite (Mg₅[(CO₃)₄(OH)₂]·4H₂O). This approach eliminates the energy-intensive step of producing high purity CO₂ associated with regenerating the solvent, and redissolving CO₂ to produce magnesium carbonate. Interestingly, while temperatures below 50 °C facilitate CO₂ capture, the mineralization kinetics are slow. However, at higher temperatures, accelerated carbon mineralization is favored by the faster kinetics of Mg(OH)₂ dissolution and precipitation of magnesium carbonate. Reacting Mg(OH)₂ at 90 °C with 15 wt% solids in the presence of 2.5 M sodium glycinate after 3 hours under well-stirred conditions results in an extent of carbon mineralization of 75.5%. The theoretical maximum extent of carbon mineralization when hydromagnesite is formed is 80%. Pre-loading CO₂ on the solvent is also an effective approach to ensure that sufficient CO₂ is available for reactive CO₂ capture and mineralization, particularly when dilute CO₂ and N₂ mixtures are used. Higher extents of carbon mineralization are associated with an increase in the particle size and a reduction in the cumulative pore volume. These insights unlock the feasibility of harnessing reactive CO₂ capture and mineralization as a pathway to convert magnesium-hydroxide bearing resources into industrially relevant magnesium carbonate products.

Keywords: Reactive CO₂ capture and mineralization; Magnesium hydroxide; Magnesium carbonate; Regenerable CO₂ capture solvents; Hydromagnesite.