Wei Chen

Electrocatalytic CO2 conversion to high-energy-density ethanol is vital for the sustainable development of society and economy, yet challenges remain in achieving high selectivity at ampere-level current densities. Herein, we rationally engineer a 1,3-dimesitylimidazol-2-ylidene (IMes)-functionalized copper hollow fiber penetration electrode (IMes-Cu HPE) for ampere-level CO2 electroreduction to ethanol. The strong electron-donating properties of N-heterocyclic carbenes (NHCs) modulate the electronic structure of the Cu active sites, effectively steering the evolution of the *CH2CHO intermediate toward the ethanol pathway to enhance selectivity. Concurrently, the unique “gas-penetration effect” inherent to the hollow fiber electrodes reinforces mass transfer and triple-phase boundary reactions, facilitating efficient ethanol synthesis. By systematically optimizing the IMes coverage and the specific adsorption of electrolyte Cl– anions, a remarkable ethanol Faradaic efficiency (FE) of 55.5% and a peak C2+ FE of 80.5% are achieved at a current density of 2.5 A cm–2. This study provides fundamental insights into the synergistic design of electrode configurations and molecular interfacial functionalization for highly efficient CO2-to-ethanol conversion.

CO2 geological storage in deep coal seams provides dual benefits of carbon storage and enhanced coalbed methane recovery. However, the CO2–water–coal interactions during storage significantly deteriorate the coal’s mechanical properties through swelling and softening mechanisms, seriously threatening reservoir stability and long-term storage integrity. Therefore, the complex effects of multi-fluid interactions on the mechanical properties of the reservoir still require thorough investigation. Consequently, at a constant temperature of 50 °C, we conducted a series of experiments under vacuum, 5 MPa CO2, 10 MPa CO2, 10 MPa deionized water, and 10 MPa CO2–water coupled conditions. The key findings are as follows: (1) water plays a dominant role in the deterioration of coal strength, with high-pressure deionized water causing the most pronounced mechanical degradation, primarily because the scale of fractures induced by clay mineral swelling upon water absorption is far larger than that caused by CO2 adsorption; (2) under CO2 saturation, the mechanical parameters of coal samples degrade in an approximately linear manner over time. Supercritical CO2, owing to its stronger adsorption affinity and higher penetration capacity, inflicts significantly greater damage than subcritical CO2; (3) the coupled action of CO2 and water exhibits distinctive damage characteristics: CO2 can penetrate smaller microfractures and, in synergy with water, form a denser internal microcrack network, resulting in the most pronounced reductions in wave velocity and increases in porosity in the coupled group. However, the competitive adsorption between water and CO2 constrains the superposition of their respective damage effects, resulting in a smaller reduction in mechanical strength under coupled conditions than in the water-only saturated group. These findings provide a comprehensive theoretical foundation for assessing the long-term stability of CO2 storage projects in deep coal seams under complex geological conditions.

Electrocatalytic CO ₂ reduction offers a sustainable pathway to produce high‐energy‐density ethanol fuel. However, achieving highly selective ethanol production at ampere‐level current densities remains a significant challenge. Herein, we report the development of a novel 1,3‐dimesitylimidazol‐2‐ylidene (IMes)‐modified Cu hollow fiber penetration electrode (IMes‐Cu HPE) leveraging the strong σ‐donating property of N‐heterocyclic carbenes (NHCs) to enhance both selectivity and efficiency toward ethanol. At a current density of 2.5 A cm ⁻² , the IMes‐Cu HPE achieves a remarkably high faradaic efficiency (FE) of 57% for ethanol and over 81% for C ₂₊ products. In situ spectroscopic analysis and density functional theory (DFT) calculations reveal that IMes modification alters the microenvironment on the Cu HPE surface and enhances the electron density of Cu active sites. This regulation facilitates the lowering of energy barriers for key intermediate formation and asymmetric C─C coupling, promoting ethanol generation. This work presents a promising strategy of molecular interface engineering for efficient CO ₂ ‐to‐ethanol conversion at industrially relevant current densities.

Selective CO₂ hydrogenation into CO via the reverse water-gas shift (RWGS) reaction is a pivotal route for large-scale carbon abatement, yet it remains hindered by the scarcity of efficient and scalable catalysts. Here, we report the construction of a high-performance Ni/TiO₂ catalyst by encapsulating in an in situ-created, robust carbon layer for boosting CO₂ conversion and CO selectivity. Mechanistic studies reveal that this catalyst follows an oxygen-vacancy-mediated redox pathway that spatiotemporally decouples CO₂ and H₂ activation, thereby offering a straightforward route to mitigate the activity-selectivity trade-off inherent in RWGS catalysis. The carbon overlayer, featuring a substantially lower hydrogen diffusion barrier than the bare TiO₂ surface, serves as a hydrogen spillover highway that generates abundant and distal oxygen vacancies on TiO₂, thereby driving efficient CO₂ dissociation. While ensuring effective H₂ activation through the formed surface Ni-C species, the carbon overlayer suppresses CO adsorption on Ni by blocking charge transfer, thus inhibiting the undesirable side reactions of methanation and CO disproportionation. This dual functionality enables the carbon-coated Ni/TiO₂ catalyst to sustain equilibrium CO₂ conversion with a near-100% CO selectivity for over 500 h under industrially relevant conditions, outperforming the majority of previously developed catalysts. Decorating an economical and effective carbon layer for geometric and electronic tuning provides a promising avenue for the design of novel hydrogenation catalysts.

Microalgae CO₂ biofixation presents an environmentally sustainable approach for mitigating CO₂ emissions from coal-fired flue gas. However, its widespread application remains limited due to high production costs, raw material safety concerns, and the small market size for microalgae biomass. In contrast, microalgae fertilizer has been drawing increasing attention due to their substantial market potential, cost-effectiveness, and environmental benefits. In this study, a strain of Chlorella sorokiniana (C. sorokiniana ) with high tolerance to ultra-low flue gas was screened from eight microalgae strains, and its maximum biomass reached 3.02 g L^- 1 within 7 days under ultra-low flue gas conditions. During cultivation, the culture system captured and transformed the flue gas components (CO₂, NO_x and SO₂), which resulted in 211-fold, 0.19-fold and 12-fold increases in total carbon, total nitrogen and sulfate contents compared to the original BG11 culture medium, respectively. This process effectively upgraded inorganic flue gas pollutants into readily available nutrients for crop growth. In addition, C. sorokinian also synthesized valuable biostimulants, including amino acids (e.g., 22.3 mg L^- 1 lysine and 20.68 mg L^- 1 glutamic acid) and plant hormones (e.g., 14.21 µg L^- 1 salicylic acid and 16.82 µg L^- 1 indole-3-acetic acid). The potential of C. sorokiniana suspension and its lysate as fertilizer were confirmed through lettuce cultivation experiments. Application of C. sorokiniana suspension at all tested doses significantly promoted plant growth, resulting in increases of 7.7-15.6% in fresh shoot weight, 3.3-15.1% in root length, and 4.2-18.4% in root fresh weight. It also improved lettuce quality, increasing the contents of vitamin E and soluble sugars by 19.6-43.9% and 4.9-41.7%, respectively. A similar promoting effect was also observed with the application of C. sorokiniana lysate at different doses. This study provides a feasible technical pathway for achieving flue gas carbon capture and resource utilization based on microalgae.

Calcium looping dry reforming of methane (CaLDRM), which realizes CO ₂ capture and in situ conversion to valuable syngas, presents a promising route for large‐scale CO ₂ fixation. However, its development is hindered by the scarcity of efficient and durable dual‐functional materials (DFMs) that combine high capture capacity with stable catalytic activity. Herein, we construct a Ni‐MgO/CaO DFM by engineering NiO‐MgO solid solution (Mg _x Ni _1‐x O) on a hierarchically porous CaO support incorporating highly dispersed MgO. The modulated Mg _x Ni _1‐x O phase fosters a strong metal‐support interaction to inhibit Ni agglomeration and carbon deposition, and simultaneously acts as a structural stabilizer to mitigate CaO sintering. The resultant material delivers a CO ₂ uptake of 11.5 mmol g ⁻¹ , an in situ CO ₂ conversion of 90 %, and a syngas yield of 55 mmol g ⁻¹ at a relatively low temperature of 620°C, while exhibiting insignificant deactivation over 65 cycles, outperforming the previously developed CaO‐Ni based DFMs. Mechanistic studies reveal that this material achieves a reaction‐induced reversible reconstruction during the CaLDRM process, which not only sustains the Mg _x Ni _1‐x O‐mediated structural stability enhancement but also ensures the high accessibility of catalytic sites, thereby decoupling the activity‐stability trade‐off. This work provides a practical material design strategy for efficient CO ₂ capture and catalytic conversion processes.

Swine wastewater is a high-strength agricultural effluent characterized by high organic loading, elevated ammonium nitrogen and phosphorus concentrations, and frequently low C/N ratios, which make simultaneous pollutant removal and resource recovery challenging. Conventional physicochemical, anaerobic, and aerobic treatment technologies are widely used, but they are often constrained by high energy demand, ammonia inhibition, insufficient nitrogen recovery under low C/N conditions, and limited resource valorization. This review comparatively evaluates these conventional technologies alongside microalgal and algal–bacterial symbiotic (ABS) systems for swine wastewater treatment and resource recovery. Particular attention is given to algal–bacterial interactions, oxygen and carbon exchange, nitrogen and phosphorus removal pathways, reactor configurations, key operational parameters, and biomass valorization routes. The reviewed evidence shows that conventional anaerobic–aerobic systems generally achieve stable COD removal (>80%) but often provide limited nitrogen recovery, whereas microalgal systems can remove 80–90% of nitrogen and phosphorus but remain restricted by ammonia toxicity, light attenuation, and biomass harvesting costs. Under optimized conditions, ABS granular systems have achieved >90% COD removal, >80% total nitrogen removal, and 70–95% total phosphorus removal, while also improving biomass settleability and process stability. Overall, ABS systems offer a promising route to shift swine wastewater treatment from discharge-oriented pollution control toward resource-oriented management. Future research should prioritize reactor scale-up, long-term operational stability, biological monitoring, and economically viable biomass valorization.