Production Of Value-added Chemicals Research Articles

Steering Acid-Base Site Distribution and Hydrophobicity of Bioresourced Bifunctional Hybrid Materials for Direct Synthesis of γ-Valerolactone from Biomass-Based Furfural.

The direct production of value-added chemicals from biomass via multiple conversion processes with a sole renewable solid catalyst is promising for carbon-neutral development while challenging. Herein, a series of novel bioresourced organic-inorganic hybrid materials were synthesized from bio-based ascorbic acid (Vc), zirconium chloride (ZrCl4) and p-toluenesulfonic acid (p-TSA) through a facile solvothermal process. The as-prepared Zr-Vc-3 catalyst with Vc, ZrCl4, and p-TSA in the 1 : 1:0.5 molar ratio displayed outstanding performance in direct furfural-to-γ-valerolactone (GVL) transformation, giving an ultrahigh GVL yield of 76.2 %, with an ideal activation energy (55.46 kJ mol-1), outperforming state-of-the-art catalysts. The superior performance of Zr-Vc-3 could be ascribed to its good reusability, relatively large pore size, suitable amount of acid-base sites, and good hydrophobicity. Mechanistic studies unveiled that Lewis acid-base sites facilitate the conversion of furfural to furfuryl alcohol and isopropyl levulinate (IPL) to 4-hydroxypentanoate via transfer hydrogenation process, while Brønsted acid sites are instrumental in the ring-opening of furfuryl alcohol to IPL and the lactonization of 4-hydroxypentanoate to GVL, overall contributing to the multi-step conversion of furfural to GVL in a single pot. This work provides a valuable reference for precisely constructing bio-based OIHMs with tailored functionalities for the one-pot valorization of biomass feedstocks via tandem reactions.

An Efficient Tri-Conductive Electrode for Ethane Direct Electrochemical Dehydrogenation on Proton Ceramic Electrolysis Cells.

The preparation of ethylene from ethane, a main component of shale gas, has become an important process of the petrochemical industry, using ethane steam cracking at high temperatures (>900 °C), which is a highly energy intensive industry. Here, direct dehydrogenation of ethane is engineered electrochemically to produce ethylene and hydrogen in a proton-conducting electrolysis cell, achieving over 50% ethane conversion and 90.42% ethylene selectivity at 700 °C. On the basis of constructing NiCu bimetallic alloy nano-catalyst on the surface of perovskite Sr3Fe2O7, Hafnium (Hf)element is doped in the bulk phase to improve proton conductivity, establish triple conductivity, and achieve efficient directional conversion of ethane. The carbon dioxide reduction reaction at the cathode is further coupled, resulting in a higher conversion of ethane on the anode side and the production of syngas on the cathode side. This electrochemical reaction process provides a choice for the clean production of high value-added small molecule chemical products.

Efficient Electrosynthesis of Valuable para-Benzoquinone from Aqueous Phenol on NiRu Hybrid Catalysts.

Electrocatalytic oxidation of aqueous phenol to para-benzoquinone (p-BQ) offers a sustainable approach for both pollutant abatement and value-added chemicals production. However, achieving high phenol conversion and p-BQ yield under neutral conditions remains challenging. Herein, we report a Ni(OH)2-supported Ru nanoparticles (NiRu) hybrid electrocatalyst, which exhibits a superior phenol conversion of 96.5% and an excellent p-BQ yield of 83.4% at pH 7.0, significantly outperforming previously reported electrocatalysts. This exceptional performance benefits from the triple synergistic modulation of the NiRu catalyst, including enhanced phenol adsorption, increased p-BQ desorption, and suppressed oxygen evolution. By coupling a flow electrolyzer with an extraction-distillation separation unit, the simultaneous phenol removal and p-BQ recovery are realized. Additionally, the developed electrocatalytic system with the NiRu/C anode displays good stability, favorable energy consumption, and reduced greenhouse gas emissions for phenol-containing wastewater treatment, demonstrating its potential for practical applications. This work offers a promising strategy for achieving low-carbon emissions in phenol wastewater treatment.

Exploring the Photocatalytic Cleavage Pathway of the β-5 Linkage Lignin Model Compound on Carbon Nitride.

As a globally abundant source of biomass, lignocellulosic biomass has been the centre of attention as a potential resource for green energy generation and value-added chemical production. A key component of lignocellulosic biomass, lignin, which is comprised of aromatic monomers, is a potential feedstock for value added chemical production. The cleavage processes of the linkages between monomers to obtain high value products, however, requires significant investigation as it is a complex, non-facile process. This study focuses on the photocatalytic valorization of a β-5 lignin model compound, a key linkage in the lignin structure. It was found that greater yields of aromatic products were obtained from the photocatalytic conversion of β-5 lignin model compound using carbon nitride (CN) when compared to Evonik P25 titanium dioxide (TiO2). Products of the β-5 model compound photocatalytic conversion were determined and C-C bond cleavage was observed. It was also determined that the solvent participated in the reactions with the introduction of a cyano group to one of the products. Radical quenching experiments revealed that superoxide radicals participated in the CN photocatalytic conversion. These results reveal for the first time the products and possible mechanism of the photocatalytic transformation of β-5 model compounds using CN photocatalysis.

Catalytic hydrogenation of CO2 by composite nickel species supported on KCl-doped graphitic carbon nitride under normal temperature and atmospheric pressure

CO2 can be used as a cheap C1 feedstock to produce value-added chemical products and fuels. In this work, it was proposed for the first time that potassium chloride-doped graphitic carbon nitride-supported composite nickel species (CNS/KCl-g-C3N4) was prepared to catalyze CO2 hydrogenation with potassium borohydride (KBH4) as a hydrogen donor to produce formate at normal temperature and atmospheric pressure. The catalytic activity of CNS/KCl-g-C3N4 reached the best when the nickel loading was optimized as 15 wt%. By using CNS/KCl-g-C3N4, the hydrogen production volume and rate of KBH4 hydrolysis were reduced by 49 % and 32 %, respectively, while the formate concentration was increased by 43 %. It was speculated that the catalytic hydrogenation of CO2 was enhanced due to the chemical adsorption of CO2 on the catalyst surface by interacting with the K-N bonds and -NH2 groups, and the formation of BH4-n(OH)n- (n=0–3) with higher activity from BH4- on the Ni0 sites.

Recycling copper wire waste into active Cu-based catalysts for value-added chemicals production via CO2 electrochemical reduction

The CO2 electroreduction reaction (CO2RR) is a method for producing value-added compounds from CO2. This study aimed to use copper from wiring waste to create Cu-based catalysts on Vulcan XC-72R carbon for converting CO2 into valuable chemicals. Copper nanopowder with an average crystallite size of 27 nm derived from the wiring waste solution was utilized as the starting material for mono and bimetallic catalysts preparation. During the bimetallic PdCu/C catalyst synthesis, a galvanic displacement reaction between Pd and Cu occurred, resulting in the formation of PdCu alloy and a reduction in the copper crystallite size. The inclusion of Pd on Cu/C in CO2RR decreased the onset potentials for C1 and C2 chemical production. The yields of methanol, formic acid, and formaldehyde products were generally increased as the Pd:Cu ratio increased. The 1:2-PdCu/C exhibited the smallest crystallite size and an onset potential of less than −1.0 V, resulting in the highest Faradaic efficiency of the products. This catalyst converted CO2 into formic acid (FE = 71.5 %) at a potential of −0.8 V and methanol (FE = 65.4 %) at −0.5 V. The catalyst’s stability was demonstrated for more than 6000 s at current densities of approximately 2 mA /mgcatalyst.

High-throughput optimization of organic carbon provision strategies enables enhanced arachidonic acid production in novel microalgae

BackgroundMicroalgae are potential sustainable resources for the production of value-added chemicals that can be used as biofuels, pharmaceuticals, and nutritional supplements. Arachidonic acid (ARA), a omega-6 fatty acid, plays a crucial role in infant development and immune response, and can be used in cosmetics and pharmaceuticals. Demand for industrial-scale ARA production is continuously increasing because of its broad applicability. To address this demand, there has been a significant shift towards microorganism-based ARA production. To accelerate large-scale ARA production, it is crucial to select suitable strains and establish optimal culture conditions.ResultsHere, we isolated a novel microalga Lobosphaera incisa CFRC-1, a valuable strain that holds promise as a feedstock for ARA production. Optimal cultivation conditions were investigated using a high-throughput screening method to enhance ARA production in this novel strain. Out of 71 candidates, four organic carbon substrates were identified that could be utilized by L. incisa CFRC-1. Through flask-scale verification, fructose was confirmed as the optimal organic carbon substrate for promoting microalgal growth, total lipid accumulation, and ARA production. Subsequently, we investigated appropriate substrate concentration and cultivation temperature, confirming that the optimal conditions were 30 g L− 1 of fructose and 27 ℃ of temperature. Under these optimized conditions, biomass and ARA production reached 13.05 ± 0.40 g L− 1 and 97.98 ± 7.33 mg L− 1, respectively, representing 9.6-fold and 5.3-fold increases compared to the conditions before optimization conditions. These results achieved the highest biomass and ARA production in flask-scale cultivation, indicating that our approach effectively improved both production titer and productivity.ConclusionsThis study presents a novel microalgae and optimized conditions for enhancing biomass and ARA production, suggesting that this approach is a practical way to accelerate the production of valuable microalgae-based chemicals. These findings provide a basis for large-scale production of ARA-utilizing microalgae for industrial applications.

Highly-dispersed CdS nanoparticles coating hierarchical Ni@NC derived from ultrathin nanosheets NMOF-Ni: Photocatalytic hydrogen evolution coupled with alcohol oxidation

Photocatalytic water-splitting into H2 in conventional procedures often requires sacrificial agents to consume unutilized holes to boost the reaction. Herein, we cast off the dependence on the addition of sacrificial agents and develop a dual-functional photocatalyst CdS/Ni@NC for coupling H2 evolution with value-added benzyl alcohol (BA) oxidation in anaerobic aqueous solution, wherein CdS/Ni@NC was synthesized by in-situ anchoring of CdS nanoparticles (NPs) onto NMOF-Ni ultrathin nanosheets-derived nitrogen-doped wrinkled graphitic carbon layers encapsulated metallic Ni NPs (Ni@NC). The optimized photocatalyst CdS/Ni@NC(5) achieves a high visible-light-driven H2 evolution rate of 1881 μmol·g−1·h−1 and a benzaldehyde (BAD) yield of 3254.2 μmol·g−1·h−1, with nearly 100 % selectivity over a 6 h period, which are 32.6 and 10.5 folds of that for CdS alone, respectively. Further in-depth experimental characterizations reveal that the hierarchical Ni@NC serves as an ideal support to enable high dispersion of CdS NPs, thus improving light absorption and facilitating full contact with reactants. Besides, the widely distributed Ni NPs, effectively shielded by nitrogen-doped wrinkled graphitic carbon layers, can not only promote photogenerated charge transfer for enhanced H2 production but also facilitate the cleavage of the Cα–H bond in BA, contributing to achieving high aldehyde selectivity. This study, integrating carbonized ultrathin nanosheets NMOF-Ni with CdS to synergistically enhance surface redox reactions, holds significant promise for advancing the development of high-performance photocatalysts for integrated production of solar hydrogen and value-added solar chemicals.

Engaging the Concepts of Bimetallicity and Mechanical Strain for N2 Activation: A Computational Exploration.

N2 activation is a vital step in the process toward NH3 production. NH3 synthesis has been considered a crucial process for the production of value-added chemicals and/or hydrogen carriers over recent years. In this work, density functional theory (ab initio) calculations are implemented for a thorough screening of bimetallic alloy surfaces using Fe, Ru, and Mo as the matrix (host) metals and Ag, Au, Co, Cu, Fe, Mo, Ni, Pd, Pt, Rh, and Rh as heterometals toward exploring the N2 catalytic activation (electronic and chemical characteristics); the monometallic surfaces are used for critical comparison in terms of their N2 activation behavior. In particular, adsorption geometries/energetics, density of states (DOS), and charge transfer are discussed. From the N2 activation on the surfaces, we could precisely capture the transition state of the N2 dissociation reaction/step. The effect of the metal alloying (geometrical and electronic factors) as well as the effect of applied mechanical strain, as a tuning factor of alloying, are both studied and thoroughly discussed. DOS studies revealed that the d-band center moved toward the negative direction for all late-TM-based alloys, thereby allowing the nitrogen molecule to adsorb weakly as compared to the early-TM surface alloys. In terms of the mechanical strain, for most of the alloy surfaces studied, apart from the Mo/Fe(110) one, the N2 binding energy varies as a linear function of the applied strain. The mechanical effect trend is in agreement with the charge transfer descending order followed: Fe/Mo(110) > Rh/Mo(110) > Au/Mo(110) > Pt/Mo(110) > Ni/Mo(110) > Ru/Mo(110) > Cu/Mo(110) > Ag/Mo(110) > Pd/Mo(110) > Au/Mo(110), pointing out that Fe-functionalized Mo(110) surface presents the highest charge transfer of -2.14 |e| to the N2 molecule. This study aspires to provide navigation criteria through the abundant design criteria of N2 activation catalysts.

A CO2-emission free direct methanol fuel cell for simultaneous production of electrical energy and value-added chemicals

It remains challenges to efficiently convert carbon-based fuels such as methanol from CO2 into electrical energy while without CO2 greenhouse gas emission. Herein, a CO2-emission free direct methanol fuel cell (DMFC) has been realized through using unique Pt-CoOOH/nickel foam anode with high electro-catalytical selectivity, activity and stability. The DMFCs demonstrate simultaneous production of 18 mol of formate for every 1 kWh of electricity output with peak power density of 49.3 mW cm−2 and high selectivity of formate value-added chemicals up to 96 %. Moreover, this simple procedure does not consume energy while output electricity compared to the traditional formate production. It either does not use the toxic feedstock of CO and the reaction conditions are very mild. The in-situ Raman test indicates that CoOOH acts as an auxiliary active site to promote the conversion of *HCO to *HCOOH and improve the selectivity of formate. In-situ IR tests and density functional theory (DFT) calculations confirm that methanol tends to be oxidized selectively into formate rather than complete-oxidizing into CO2. This study achieves clean and efficient utilization of carbon-based fuels to co-generate electrical energy and value-added chemicals while no CO2 greenhouse emission, even realize the “negative carbon” cycle.

Efficient hole extraction to reactive oxidation sites over a Co3O4/Cs3Sb2Br9 p-n heterojunction for enhanced benzylic C(sp3)-H bond oxidation

Photocatalytic selective oxidation of aromatic hydrocarbons plays an important role in the production of value-added chemicals. A key step in this process is the activation of C(sp3)-H bond by photogenerated holes. However, the inadequate hole generation and lack of surface adsorption-activation sites severely hinders the improvement in photocatalytic C-H bond oxidation. In particular, the random charge migration to the surface impedes the effective capture of holes by surface active sites to dissociate the C(sp3)-H bond. Here, we design and fabricate a Co3O4/Cs3Sb2Br9 p-n heterojunction that effectively addresses these challenges. The p-n heterojunction forms strong built-in electric fields (BEF) facilitating spatial charge separation. Holes are accumulated on Co3O4, while electrons are accumulated on Cs3Sb2Br9, thereby offering abundant active holes and electrons. Moreover, Co3O4 shows stronger adsorption and activation capacity for the C(sp³)-H bond, enabling the C(sp3)-H bond dissociation with low reaction energy barrier. Consequently, the holes are directionally extracted from photoactive Cs3Sb2Br9 to catalytically active Co3O4 under visible light irradiation, thereby accelerating the toluene oxidation. The optimized 5 % Co3O4/Cs3Sb2Br9 exhibits a benzyl aldehyde (BAD) evolution rate of 5044 μmol g−1 h−1 and a benzyl alcohol (BA) production rate of 1820 μmol g−1 h−1, which are 12 and 17 times higher than that of blank Cs3Sb2Br9, respectively.

An efficient Au/ZnO catalyst for the photocatalytic conversion of methane to formaldehyde

The photocatalytic oxidation of methane to value-added chemical products under mild conditions is crucial for resource utilization and environmental protection. However, inefficient generation of reactive oxygen species partially limits methane activation. To tackle this issue, we have developed highly dispersed Au-modified ZnO nanosheets through photo-deposition method for the photocatalytic oxidation of methane to formaldehyde. The optimized Au0.1/ZnO catalyst (0.1 wt% Au on ZnO) achieves a HCHO yield of 19.14 μmol h−1 with a selectivity of 87.94 %. Electron paramagnetic resonance, Raman, X-ray photoelectron spectroscopy and density functional theory show that Au enhances the concentration of oxygen vacancies (OVs) in ZnO. This enhancement is attributed to a strong interaction between Au and ZnO, which facilitates the transfer of electrons from the ZnO surface to Au. Under irradiation, Au and OVs function as hole and electron acceptors, respectively. This interaction promotes carrier separation, reduces charge recombination, enhances oxygen adsorption, and effectively generates reactive oxygen species, such as ·OH. Subsequently, CH4 is oxidized to ·CH3 by holes from Au. Concurrently, O2 is reduced by electron from OVs, following the pathways O2 → OOH→H2O2 → ·OH. The rapid oxidation of CH3OH by ·CH3 and ·OH results in the formation of HCHO.

CoNiOOH nanosheets array enables highly effective value-added chemicals production via nitrite and sulfide electrolysis

Here, we show that the CoNiOOH nanosheets array can be applied for catalyzing nitrite reduction and sulfide oxidation reactions (NO2RR and SOR) simultaneously, realizing NH3 production and synchronous desulfuration. As a result, the catalyst achieves a maximal Faradic efficiency of 93 % with the corresponding yield rate of 14.6mg h−1 cm−2 for NH3 production and high robustness over 4 consecutive cycles. Beyond that, it could trigger the SOR with a low potential of 0.65 V vs RHE to reach 100 mA cm−2, far lower than that needed for the water oxidation (1.62 V vs RHE). More importantly, the coupling system composed of NO2RR and SOR could realize value-added products on both sides. Theoretical and experimental analyses validate that Ni regulates the electronic structure of Co site, which optimizes the activation and adsorption of reactants and intermediates, and thus reduce the energy barriers, accounting for the performance enhancement.

Highly Self-Healing Co3+/Ni3+ Dual-Active Species for the Electrocatalytic Oxidation of 5-Hydroxymethylfurfural.

Electrocatalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is significant for the sustainable production of value-added chemicals. Active sites of catalysts could enhance the activity and selectivity of the HMF oxidation reaction (HMFOR), but the self-healing ability of active sites has been commonly ignored. In this work, Co(OH)2/Ni-MOF was successfully fabricated for efficient oxidation of HMF to FDCA under mild conditions. Electrochemical and cyclic stability experiments demonstrated the high self-healing properties of the dual active sites (Co3+/Ni3+). So, the retention rate of FDCA yield can still reach 98.5%, even after 90 days. HMFOR was further coupled with 4-nitrophenol hydrogenation, which promotes the yield and Faradaic efficiency of FDCA to about 100%. Therefore, this study explores the self-healing properties of species and provides new insights for designing efficient catalysts.

High value-added chemical production through anaerobic codigestion of corn straw with a microbial consortium, cow manure and cow digestion solution

ObjectivesThis study investigated the codigestion of corn straw (CS) with cow manure (CM), cow digestion solution (CD), and a strain consortium (SC) for enhanced volatile fatty acid (VFA) production. The aims of this study were to develop a sustainable technique to increase VFA yields, examine how combining microbial reagents with CS affects VFA production by functional microorganisms, and assess the feasibility of improving microbial diversity through codigestion. MethodsBatch experiments evaluated VFA production dynamics and microbial community changes with different combinations of CS substrates with CM, CD, and SC. Analytical methods included measuring VFAs by GC, ammonia and chemical oxygen demand (COD) by standard methods and microbial community analysis by 16S rRNA gene sequencing. ResultsCodigesting CS with the strain consortium yielded initial VFA concentrations ranging from 0.6 to 1.0 g/L, which were greater than those of the other combinations (0.05–0.3 g/L). Including CM, and CD further increased VFA production to 1.0–2.0 g/L, with the highest value of 2.0 g/L occurring when all four substrates were codigested. Significant ammonium reduction (194–241 mg/L to 29–37 mg/L) and COD reduction (3310–5250 mg/L to 730–1210 mg/L) were observed. Codigestion with CM and CD had greater Shannon diversity indices (3.19–3.24) than did codigestion with the other consortia (2.26). Bacillota dominated (96.5–99.6 %), with Clostridiales playing key roles in organic matter breakdown. ConclusionsThis study demonstrated the feasibility of improving VFA yields and harnessing microbial diversity through anaerobic codigestion of lignocellulosic and animal waste streams. Codigestion substantially enhanced VFA production, which was dominated by butyrate, reduced ammonium and COD, and enriched fiber-degrading and fermentative bacteria. These findings can help optimize codigestion for sustainable waste management and high-value chemical production.

Correlative in situ analysis of the role of oxygen on ammonia electrooxidation selectivity on NiOOH surfaces

The electrochemical ammonia oxidation reaction (AOR) offers a promising pathway for environmental remediation, energy conversion, and the production of value-added chemicals. Although NiOOH shows potential as an efficient catalyst for AOR, the underlying mechanism and the influence of the concurrent oxygen evolution reaction (OER) are not yet fully understood. Here, the AOR mechanism on NiOOH is examined, emphasizing the influence of OER and dissolved O2. Using differential electrochemical mass spectrometry (DEMS), Raman spectroelectrochemistry, UV–vis spectroelectrochemistry, and attenuated total reflection infrared reflection (ATR-IR) spectroelectrochemistry, we reveal that the NiOOH formation, AOR activity, selectivity, and deactivation as well as the reaction intermediates are significantly modulated by OER and dissolved O2. AOR on NiOOH is potential-dependent: N2production starts with the onset of OER, while extensive NOx and NO2/3− species form at higher potentials. The OER competes with the AOR-to-N2 pathway but promotes AOR-to-NOx, where the presence of O2 mitigates OER deactivation on NiOOH. Our findings highlight the advantage of correlative in situ analysis in studying electrocatalytic processes and advance the current understanding of AOR pathways on NiOOH toward energy and environmental applications.

A novel two-step process for the synthesis of hexamethylenediamine from 6-hydroxyhexanenitrile derived from ε-caprolactone

Hexamethylenediamine (HMDA) is an important chemical product for the production of various value-added chemicals especially in the manufacture of polyamides, and its current production mainly relies on the hydrogenation of adiponitrile (ADN). However, the processes for the production of ADN are complicated and monopolized by some transnational corporations. In this work, a novel two-step synthesis of HMDA, consisting of the aerobic oxidation of 6-hydroxyhexanenitrile (6-HHN) to 5-cyanopentanal (5-CPA) and the reductive amination of 5-CPA to HMDA, has been developed. The aerobic oxidation of 6-HHN to 5-CPA was readily realized in an excellent yield of 92.2% under the catalysis of a classic catalyst system Fe(NO3)3/4-AcNH-TEMPO/NaCl under mild conditions. The reductive amination of 5-CPA to HMDA was conducted over a bimetallic Ni30Co7/SiO2, and the conversion of 5-CPA was 99.0% with a HMDA selectivity of 89.5% under optimal parameters. The characterization results show that Ni and Co are mainly present in the form of a Ni-Co alloy. The formation of the Ni-Co alloy in the catalyst Ni30Co7/SiO2 endows with a synergistic effect between Ni and Co in the reductive amination of 5-CPA to HMDA. Catalyst deactivation occurs during catalytic run. Deactivation is mainly due to the metal agglomeration, the oxidation of Ni0 to Ni2+, and the carbon deposition. Deactivated catalysts can be completely regenerated by H2 high-temperature reduction.

Enhanced solar urea synthesis from CO2 and nitrate waste via oxygen vacancy mediated-TiOx support lead-free perovskite

The nitrogen fertilizer industry, particularly urea production, notably contributes to greenhouse gas emissions and energy consumption. Urea synthesis via solar energy encounters several challenges. Specifically, solar urea synthesis methods often exhibit low efficiency and yield, primarily stemming from inefficient energy conversion processes and intricate reaction pathways. Moreover, the kinetics of the urea synthesis reaction may be sluggish, thereby impacting the overall production rate. Therefore, in this study, we introduce a novel electron-reserve-enhanced Cs2CuBr4/TiOx-Ar (CCBT-Ar) structure for the photocatalytic synthesis of urea from CO2 and nitrate waste. Theoretical calculations and spectroscopic analysis underscore the critical role of oxygen vacancies (Ov) within the amorphous TiOx shell, enhancing reactant adsorption and catalyzing the rate-determining step (*OCONH2→*HOCONH2). However, the presence of Ov also results in significant carrier recombination, acting as trapping centers and reducing urea production activity. Importantly, we demonstrate that in-situ-grown carbon nanosheets, in conjunction with TiOx, function as efficient electron reservoirs, markedly mitigating trapping-induced recombination and facilitating electron redistribution. These reserved electrons can then actively participate in the urea synthesis process. As a result, the electron-reserve-enhanced structure exhibits robust solar urea yield and selectivity, even in challenging wastewater conditions. This work provides a rational and innovative approach to catalyst development in complex solar synthesis, offering promising avenues for the sustainable production of value-added chemicals while concurrently reducing carbon emissions.

Breakthrough in CO2 Electroreduction to Multi-Carbon Products at Ampere-Level Enabled by Active Sites Engineering.

Efficient production of value-added chemicals with high selectivity from CO2 electroreduction at industrial-level current density is highly demanded, yet remains a big challenge. In a recent issue of Angewandte Chemie, Han and colleagues have elegantly increased the Faradaic efficiency (FE) of multi-carbon (C2+) products to over 70 % at amperes level (1.4 A cm-2) by engineering the active sites for the key reactions involved in the CO2 electroreduction. In this study, the highly dispersed Pd atoms have two unique functions: active sites for water dissociation and to induce the electron rearrangement of the surrounding Cu atoms to form new active sites for CO conversion, while the Cu far from Pd are the active sites for efficient CO2 conversion to CO, the synergistic functions of these three active sites result in high FE and yields of C2+ products at industrial-level current density. This research is a remarkable step forward in the methodology for developing efficient and durable catalysts for CO2 electroreduction and beyond.

A Light-Powered In Vitro Synthetic Enzymatic Biosystem for the Synthesis of 3-Hydroxypropionic Acid via CO2 Fixation.

3-Hydroxypropionic acid (3-HP) is a highly sought-after platform chemical serving as a precursor to a variety of high value-added chemical products. In this study, we designed and constructed a novel light-powered in vitro synthetic enzymatic biosystem comprising acetyl-CoA ligase, acetyl-CoA carboxylase, malonyl-CoA reductase, and phosphotransferase to efficiently produce 3-HP through CO2 fixation from acetate, a cost-effective and readily available substrate. The system employed natural thylakoid membranes (TMs) for the regeneration of adenosine triphosphate and nicotinamide adenine dinucleotide phosphate. Comprehensive investigations were conducted on the effects of buffer solutions, substrate concentrations, enzyme loading levels, and TMs loading levels to optimize the yield of 3-HP. Following optimization, a production of 0.46 mM 3-HP was achieved within 6 h from an initial 0.5 mM acetate, with a yield nearing 92%. This work underscores the simplicity of 3-HP production via an in vitro biomanufacturing platform and highlights the potential for incorporating TMs as a sustainable and environmentally friendly approach in biomanufacturing processes.