Jianchun Jiang

Vanillin (VAL) is an important lignin-derived platform compound whose multifunctional structure enables selective hydrodeoxygenation (HDO) to products with different degrees of deoxygenation. Herein, Pt/CoOx catalysts with reduction-dependent metal and oxide states were developed to regulate product distribution. Pt/CoOx-240 afforded 2-methoxy-4-methylphenol (MMP) in 95.0% yield at 90 °C after 8 h and 4-methylcyclohexanol (MCYL) in 90.4% yield at 150 °C after 8 h. Methanol and methane were quantified together with the principal liquid products to describe the detected one-carbon (C1) stream; at 210 °C, their measured yields were approximately 13.6 and 90.0%, respectively, and their nominal sum is treated as an apparent methoxy-associated C1 recovery rather than a closed carbon balance. Model-compound controls support an association between methoxy substituents and C1-product formation, although isotope labeling was not performed. Beyond model-compound conversion, Pt/CoOx-240 directly converted isolated enzymolysis lignin without a separately prepared lignin-oil intermediate, affording independently quantified unsubstituted cyclohexanol at a carbon yield of 15.7%. Characterization and catalytic comparisons are consistent with a reduction-dependent cooperative state that involves reduced Pt- and Co-containing species together with residual CoOx environments and contributes to product-distribution control. Reaction-stage process mass intensity (PMI) values were approximately 121 and 154 g g−1 for the MMP- and MCYL-forming routes, respectively, with isopropanol accounting for most of the quantified material input. The present system therefore combines switchable product selectivity, direct isolated-lignin conversion, and explicit C1-product reporting, while solvent demand remains the principal current limitation.

The modulation of metal–support interaction (MSI) could provide exciting catalytic performance for the heterogeneous catalyst. Herein, we report a novel and fast strategy to controllably modulate the physicochemical structure of supports through NIR laser irradiation and then reconstruct the interface between the metal site and support. The abundant oxygen vacancies, tunable anatase-rutile phases, and unique surface properties of TiO2 supports can be formed by laser irradiation in 3 s. It is worth mentioning that the structure and properties of TiO2 supports can be controllably modulated by controlling the intensity of laser irradiation, thereby tuning the MSI between active Ru sites and TiO2 supports to promote the catalytic performance of Ru/TiO2 catalysts. Specifically, the optimized interfacial activity of the Ru/TiO2 catalyst would exhibit excellent electron/mass transfer, which facilitates the adsorption and activation of H-donor (alcohols) and ethyl levulinate (EL), thereby improving the EL catalytic transfer hydrogenation (CTH) to γ-valerolactone (GVL), achieving 95% GVL yield, 96% EL conversion, and 99.0% GVL selectivity under mild conditions (150 °C, 12 h, 2-PrOH as H-donor). This research provides an innovative approach for fast modulation of support to tune the MSI, thus enhancing the catalytic activity of catalysts.

D-tagatose is a rare sugar that occurs naturally and combines high sweetness with a low caloric value. It has several beneficial effects, including anticariogenic activity, modulation of the intestinal microbiota, and potential benefits for diabetes management. It is used as a novel sweetener and pharmaceutical excipient in the food and pharmaceutical industries. Currently, D-tagatose is produced mainly through chemical synthesis and biocatalysis. The chemical preparation of D-tagatose requires complex product purification and entails high waste-treatment costs, while biological preparation of D-tagatose offers high catalytic efficiency, mild reaction conditions, and fewer by-products. Therefore, in recent years, the biocatalytic conversion of D-galactose into D-tagatose using L-arabinose isomerase (L-AI) has attracted considerable attention, prompting extensive efforts to develop more economical and environmentally friendly production methods. To date, L-AI from various microbial sources has been identified and characterized, and researchers have engineered L-AI into a more effective biocatalyst through mutagenesis to improve process feasibility. This paper comprehensively reviews the current status and the latest advancements in the synthesis of D-tagatose from the perspective of biocatalysis.

This study aimed to enhance the enzymatic hydrolysis efficiency of bamboo shoot shell (BSS) and establish a high solid loading fed-batch enzymatic hydrolysis strategy for pretreated BSS. BSS was pretreated with five alkaline reagents (NaOH, KOH, NaHCO₃, CH₃COONa, and Na₂SO₃). NaOH demonstrated the best enzymatic performance, with glucose and xylose yields of 96.55% and 86.56% at 2% (w/v) solid loading, respectively. Based on this outcome, NaOH pretreatment conditions were further optimized, with 3% NaOH at 110 °C for 60 min identified as optimal. The yields of glucose and xylose under this condition were 98.11% and 93.64%, respectively. The hydrolysis kinetics of NaOH-pretreated BSS were analyzed using fractal kinetic modeling to understand its hydrolysis characteristics. This analysis indicated that a solid loading effect became apparent above 12.5% (w/v). Subsequently, the simplex-centroid mixture design was employed to optimize feeding ratios at 6 h, 12 h, 24 h, and 36 h to obtain maximum sugar concentration at an initial solid loading of 20% (w/v) and a final solid loading of 40% (w/v). The total sugar concentration reached 249.55 g·L⁻¹ in the optimal fed-batch strategy by this model, which was higher than that of 225.91 g·L⁻¹ in the batch group. When the solid loading was further increased to 45% (w/v), the total sugar concentration reached 269.49 g·L⁻¹. Notably, the above strategy is limited by an enzyme loading of 15 FPU·g⁻¹ glucan and product inhibition at high solid loading, with industrial scalability still needing further exploration. Overall, this model demonstrated significant potential for increasing the sugar concentration in fed-batch strategies for pretreated biomass.

This study aimed to investigate the effect of dietary betaine on the growth, glucose and lipid metabolism, and bile acid (BA) metabolism in Micropterus salmoides fed high-cottonseed concentrated protein (CPC) diets. In this study, Micropterus salmoides were fed six experimental diets: the basal diet (BD diet; high fish meal), the low-fish meal diet (LF diet; 75% of the fish meal protein in the BD diet was substituted with CPC), and four betaine-supplemented diets (1.0 g/kg, 2.0 g/kg, 4.0 g/kg, and 8.0 g/kg of betaine were added to the LF diet, designated as LFB1.0, LFB2.0, LFB4.0, and LFB8.0, respectively). After an 8-week feeding trial, compared with the BD diet, fish fed the LF diet had decreased weight gain rate, reduced feed utilization efficiency, and poor liver health and impaired metabolic function. Conversely, fish fed the LFB4.0 diet showed an increased weight gain rate and feeding rate, improved liver antioxidant capacity, and decreased hepatic lipid droplets and glycogen content. Non-targeted metabolomics of the liver revealed that betaine regulated carbohydrate and lipid metabolism and was associated with primary bile acid metabolism. Moreover, the hepatic levels of the BA regulatory factors short heterodimer partner and farnesoid-X-receptor, as well as the gene expression of BA transporter bile salt export pump, were increased in fish fed the LFB4.0 diet. Supplementing the LF diet (high CPC levels) with 4.0 g/kg betaine improves fish growth performance and enhances hepatic carbohydrate and lipid metabolism via the positive regulation of BA metabolism by betaine.

In this study, we present a straightforward synthesis strategy to prepare transition metal sulfide electrocatalysts supported on sulfonated carbon nanotube-chitosan-derived carbon aerogel. Highly dispersed Ni3S2@CNT, Cu7S4@CNT, and Co4S3@CNT were successfully fabricated and applied for 5-hydroxymethylfurfural (HMF) electrooxidation to 2,5-furandicarboxylic acid (FDCA). Among them, Co4S3@CNT exhibited remarkable electrocatalytic activity, delivering a current density of 100 mA cm–2 at a low potential of 1.367 V (vs RHE) while attaining 99.82% HMF conversion, 99.97% FDCA selectivity and a Faradaic efficiency of 83.75%. Electrochemical measurements revealed that Co4S3@CNT possesses an electrochemical active surface area (ECSA) of 0.781 μF cm–2, which is higher than those of Ni3S2@CNT and Cu7S4@CNT, implying an increased population of active sites and enhanced catalytic activity. In-situ Raman spectroscopy reveals that Co4S3@CNT undergoes a progressive reconstruction from Co(OH)2 to CoOOH under anodic conditions, with CoOOH formation being significantly delayed in the presence of HMF, confirming its role as the active phase. Density functional theory (DFT) calculations further indicate that the excellent performance of Co4S3@CNT originates from the lowest energy barrier (1.84 eV) for the rate-determining catalyst activation dehydrogenation step, coupled with its pronounced charge-polarization capability that facilitates HMF preactivation. This work gives a promising design approach for developing efficient nonprecious metal electrochemical catalysts toward biomass valorization.

D-lactic acid is a key chiral intermediate widely applied in agriculture, pharmaceuticals, and polylactic acid synthesis, with microbial fermentation as its main production method. Commercial D-lactic acid production depends heavily on refined carbohydrates and yeast extract as carbon and nitrogen sources, resulting in prohibitive raw material costs. Abundant in microbially available proteins and carbohydrates, renewable resources can act as carbon and nitrogen substrates for efficient D-lactic acid production. Repurposing these resources reduces production expenses and is essential for the industrial scaling of D-lactic acid manufacturing. This paper reviews research advances in D-lactic acid fermentation using renewable feedstocks including agricultural wastes, sugar industry residues, oil processing wastes, and cheese processing by-products as carbon and nitrogen sources.

Large-scale membrane-electrode-assembly (MEA) CO2 electrolyzer stacks inevitably operate under heated conditions, yet the mechanistic origin of temperature-dependent selectivity shift on Cu and strategies to sustain the C2H4 selectivity remain poorly understood. Here, we show that, in MEA cells with 0.1 M KHCO3 anolyte, increasing temperature strengthens the interfacial hydrogen-bond network, thereby suppressing water dissociation to form surface-bound *H. The resulting imbalance between *H and *CO2 surface coverages limits *CO hydrogenation and C–C coupling, shifting the selectivity from C2H4 toward CO and displacing the current density for peak C2+ Faradaic efficiency (FE) to higher values. By rebalancing the relative hydrogenation environment associated with the surface coverages of *H and *CO2 through control of CO2 partial pressure, C2H4 selectivity can be recovered under elevated temperatures, reaching a peak C2H4 FE of 55–60% between 50 and 80 °C, comparable to or exceeding ambient performance. Alternatively, concentrated anolytes efficiently mitigate temperature sensitivity by weakening the hydrogen-bond network and thus improve the FE of C2H4. These insights establish a mechanistic basis for temperature-induced selectivity control of Cu-based catalysts in scalable, heated CO2 electrolyzers.