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Biolubricants produced by chemically modifying vegetable oils are promising to replace mineral-based lubricants. However, the performances of biolubricants synthesized through traditional chemical modification routes, such as transesterification/esterification, epoxidation with further ring opening, and estolide formation, cannot satisfy the demands of extreme conditions. Meanwhile, complicated multi-step reactions cause expensive costs, which hinders their large-scale application. In this study, pelargonic acid (PA) derived from the cleavage of oleic acid was esterified with trimethylolpropane (TMP) to produce branched-chain esters (tri-TMP esters) catalyzed by the lipase (Candida sp. 99–125), focusing on batch stability of the lipase, thermal-oxidation stability and lubrication performance of the product. The lipase maintained high activity for 4 continuous batches in 5 L enzyme reactor with the conversion of PA > 96% and the accumulation of tri-TMP esters > 84% in each batch. The obtained tri-TMP esters had a pour point of − 56 °C, a viscosity index of 137, and a flash point of 276 °C. Anti-oxidation stability test and thermogravimetric behaviors showed that the biolubricant had favorable thermal-oxidative stability. Friction tests verified that the product displayed excellent lubrication performance with a minimum coefficient of friction (COF) of 0.099 and an average wear spot diameter (WSD) of 221.5 µm. The green and high-selective synthetic pathway fills the defect of existing routes for the preparation of biolubricants from chemically modified vegetable oils. [Display omitted] • Lipase-catalyzed synthesis of branched-chain esters based on PA and TMP was proposed. • The lipase maintained high activity for 4 continuous batches. • The tri-TMP esters has superior low-temperature performance and thermal-oxidative stability. • This biolubricant displayed excellent lubrication performance in HFRR tests. [ABSTRACT FROM AUTHOR]

• A photo-enzyme nanosystem for CO 2 reduction was constructed. • In-CdS was prepared to improve its photocatalytic performance. • NADH regeneration yield of 10 %In-CdS@ZIF-8 is 94.10 %. • FDH was immobilized to produce 267.18 μM HCOOH. • 85.98% of the residual activity was retained after reusing 8 times. Replacement of fossil fuel by renewable resources is a central resource and energy efficiency strategy, where CO 2 is the key molecule to proceed effectively in this direction. Here, we synthesized In-doped CdS and constructed a new photo-enzyme nanosystem 10 %In-CdS@ZIF-8&FDH, which can catalyze CO 2 to formic acid (HCOOH) via formate dehydrogenase immobilized on ZIF-8 while photocatalytic regenerating NADH via indium-doped CdS. Indium doping greatly enhances the photocatalytic performance of CdS. The NADH regeneration rate reaches 94.10 %. The nanosystem can produce 267.18 μM HCOOH, which is 4.27 times that of the free enzyme system. And 85.98 % of the residual activity can be retained after reusing 8 times. This study will inspire more research efforts for light-driven enzymatic nanosystems in CO 2 fixation and lay the foundation for realizing renewable energy-driven CO 2 conversion to produce chemical products. [ABSTRACT FROM AUTHOR]