Terpenoids are widely used in clinical therapeutics and medicinal discovery, as well as play important roles in cosmetic, food and perfume industries. In nature, terpenoids are synthesized from isopentenyl pyrophosphate and dimethylallyl pyrophosphate through multistep enzymes catalysis.
　　Since terpenoids are important, developing selective synthesis of terpenoids from bulk chemicals by mimicking the biological process is necessary.
　　Recently, a team led by Prof. CHEN Qing'an from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a bioinspired and catalytic transformation of isoprene.
　　Their findings were published in Nature Communications on Nov. 04.
　　Isoprene is considered as cost-effective choice for biomimetic constructions of terpenoids due to its characteristic structure and abundance.
　　In terms of the synthesis of hemiterpenoids and acyclic monoterpenoids, various catalytic systems have been well developed under transition metal catalysis. However, there are many challenges, such as chemo-, regio- and redoxselectivities, to realize the nucleophilic cyclictelomerizations of isoprene, especially nucleophilic aromatization.
　　Nucleophilic aromatization of monoterpenes from isoprene (Image by ZHANG Weisong)
　　In this study, the researchers developed a new strategy to realize nucleophilic aromatization of monoterpenes from isoprene under nickel/iodine cascade catalysis, and it could be applied to various nucleophiles such as indoles, indazoles, benzotriazole and pyrroles.
　　In this strategy, a series of natural terpenes were transformed to aromatic C10 or C15 blocks by I2 catalysis. Based on the good tolerance of different monoterpenes, the convergent synthesis strategy was implemented smoothly by using drugs and plant extracts.
　　Meanwhile, the researchers also indicated the possible catalytic pathways of this strategy. Firstly, through the regulation of IPr ligand, the cyclodimerization of isoprene proceeded under Ni catalysis. Then, In the presence of K2S2O8, a highly selective nucleophilic addition occurred quickly following the oxidative aromatization of limonene under I2 catalysis.
　　Moreover, they realized the orthogonal C–H functionalization of two regioisomers of monoterpene with different nucleophiles in one same pot. And various hybrid terpenyl indoles were programmatically assembled to illustrate the practical utility of this protocol.
　　The above work was supported by Dalian Outstanding Young Scientific Talent and the National Natural Science Foundation of China.

　　Transition metal hydrides (TMHs) can be used as high-efficiency catalysts for hydrogen-involving reactions due to their finely modulable electronic states and reaction paths by interstitial hydrogen.
　　However, their severe thermodynamic instability brings challenges for preparation and utilization under ambient conditions.
　　Structural properties of surface ligand-confined 2D rhodium hydride (Image by FAN Jinchang)
　　Recently, a research group led by Prof. DENG Dehui and Assoc. Prof. YU Liang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) constructed novel ambient-stable two-dimensional (2D) TMHs which are rhodium hydride (RhH) nanosheets.
　　This study was published in Matter on Sep. 28.
　　TMHs are usually thermodynamically unstable with positive formation free energies under standard conditions and thus can only be formed under immense H2 pressure (at least several GPa) or highly reductive conditions.
　　So far, palladium hydride is the only-reported ambient-stable TMH owing to its relatively strong interaction between Pd and H, while preparation and utilization of novel Pd-free ambient-stable TMHs under mild conditions is still unachieved.
　　In this study, the researchers used electron-attracting n-butylamino ligands to enhance the interaction between Rh and interstitial hydrogen, making the formation of 2D RhH thermodynamically permissible. It exhibited a superior hydrogen evolution reaction (HER) activity with a lower overpotential and 3.1 times and 1.4 times higher mass activity than 2D Rh catalyst and commercial Pt/C catalyst, respectively.
　　Moreover, the theoretical calculations revealed the significant effect of interstitial H atoms and surface ligands in boosting the HER activity of Rh, by moderately weakening hydrogen adsorption and accelerating H2 desorption via a ligand-mediated H-transfer mechanism
　　This work was supported by the National Natural Science Foundation of China, National Key R&D Program of China and the Young Cross Team Project of CAS.

　　The electrochemical CO2 reduction reaction (CO2RR) into carbon-based fuels provides a promising strategy to mitigate the CO2 emission and promotes the utilization of renewable energy.
　　The Cn (n≥2) liquid products are desirable because of their high energy densities and ease of storage. However, manipulation of C-C coupling pathway remains a challenge due to the limited mechanistic understanding.
　　Recently, a research group led by Profs. ZHANG Tao and HUANG Yanqiang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has developed a Sn-based tandem electrocatalyst (SnS2@Sn1-O3G), which could reproducibly yield ethanol with a Faradaic efficiency of up to 82.5% at -0.9 VRHE and a geometric current density of 17.8 mA/cm2.
　　The study was published in Nature Energy on Oct. 30.
　　The researchers fabricated the SnS2@Sn1-O3G through solvothermal reaction of SnBr2 and thiourea on a three-dimensional carbon foam. The electrocatalyst comprised SnS2 nanosheets and atomically dispersed Sn atoms (Sn1-O3G).
　　Mechanistic study showed that this Sn1-O3G could respectively adsorb *CHO and *CO(OH) intermediates, therefore promoting C-C bond formation through an unprecedented formyl-bicarbonate coupling pathway.
　　Moreover, by using isotopically labelled reactants, the researchers traced the pathway of the C atoms in the final C2 product formed over the catalyst of Sn1-O3G. This analysis suggested that the methyl C in the product comes from formic acid whereas the methylene C was from CO2.
　　"Our study provides an alternative platform for C–C bond formation for ethanol synthesis and offers a strategy for manipulating CO2 reduction pathways towards desired products," said Prof. HUANG.
　　This work was supported by the National Natural Science Foundation of China and CAS Project for Young Scientists in Basic Research.

　　In the petrochemical industry, light linear/branched alkane isomers (C5-C7) need to be effectively separated for different end uses, linear alkanes are to be cracked for ethylene production, whereas branched isomers are to be used for gasoline upgrading.
　　Recently, a research group led by Prof. YANG Weishen and Prof. BAN Yujie from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) split linear alkanes from mono-branched and di-branched isomers as well as their cyclical counterparts through oriented metal-organic framework (MOF) membrane.
　　This study was published in Nature Communications on Oct. 19.
　　MOFs bring tremendous opportunities for membrane separation. HKUST-1 is an archetypal MOF with a combination of di-nuclear copper paddlewheel units and 1,3,5-benzenetricarboxylic acid to form a face-centered cubic network.
　　In this study, the researchers indicated that {111}-oriented HKUST-1 membranes were capable of splitting linear alkanes from branched isomers (or cyclical counterparts) by virtue of the size repulsion mechanism, since the rigid triangular pore with a size of ~0.46 nm running through {111} crystal facets was positioned between the kinetic diameters of alkane isomers.
　　The anisotropy of the porous HKUST-1 architecture and C5-C7 alkane isomer separation through {111}-oriented HKUST-1 membranes at 30°C (Image by BAN Yujie and WANG Yuecheng）
　　In this study, the {111}-oriented HKUST-1 membranes were formulated according to the morphology-biased principle and finally realized with a low dose synthesis method for terminating undesired crystal nucleation and growth. This membrane could realize one-step extraction of normal-pentane, normal-hexane and normal-heptane from a ten-component alkane isomer solution that mimicked light naphtha.
　　This work was supported by the National Natural Science Foundation of China and the Youth Innovation Promotion Association of CAS.

　　Membrane separation technology offers great potential due to its low energy consumption and continuous operation availability. Metal-organic frameworks (MOFs) are promising in separation membranes due to their abundant species, high porosity, and precise regulation of pore architectures.
　　However, the development process of high-performance MOF membranes is time-consuming and costly, and the membrane is plagued by unavoidable problems such as heterogeneous nucleation, defects, cracks, etc., resulting in the actual separation performance of MOF membranes being far lower than the theoretical simulation value, and not accurately demonstrating the separation ability of the material intrinsic pore structure.
　　The MOF membrane amount to date is only a drop in the bucket compared to the material collections. The fabrication of an arbitrary MOF membrane exhibiting inherent separation capacity of the material remains a challenge.
　　Recently, a research group led by Prof. YANG Weishen and Assoc. Prof. PENG Yuan from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has proposed a new strategy of modular customization and non-destructive regulation of MOFs for efficient membrane separations.
　　They have achieved rapid regulation of the MOF module and verified the corresponding membrane for highly accurate separation applications, which provided a solid scientific and technical foundation for the research and development of separation membranes to meet the high-efficiency separation requirements of today's bulk/specific industrial products.
　　This work was published in Angewandte Chemie International Edition on Oct. 16.
　　Diagrammatic illustrations of the MOF modular customization concept (Image by SHU lun and PENG yuan)
　　The researchers proposed a strategy to modularize custom defect-free MOF separation membranes. The membrane structure consisted of two parallel modules. One was a discrete MOF module based on the characteristics of heterogeneous mutually reinforcing nuclei, which led to the implementation of molecular mass transfer and separation by exploiting the intrinsic pore structure. The other was the highly cross-linked, ultra-low permeability polyamide module formed by the confined interface polymerization operation, which was responsible for the comprehensive blockade of defects between MOF modules.
　　Guided by this strategy, the MOF module could be randomly replaced to customize the corresponding MOF separation membrane, and high-performance MOF separation membranes could be rapidly produced. With the modified post-synthesis strategy, the MOF module skeleton in the membrane was controlled without loss and the separation accuracy was doubled.
　　The researchers selected four MOFs with different pore/channel sizes and functionalities for batch fabrication of defect-free MOF membranes. Each membrane fully displayed the separation potential according to the MOF pore size.
　　Among them, the NH2-Zn2Bim4 membrane exhibited a high H2/CO2 mixture separation factor of 1656 and H2 permeability of 964 gas permeation unit. Taking advantage of this strategy, the membrane performance could be further enhanced via application-oriented post-synthetic ligand exchange. The H2/CO2 selectivity of the regulated membrane was approximately 200% higher than that of the original membrane.
　　"This strategy provides a tractable route to customize a myriad of high-performance membranes to meet different separation requirements," said Prof. YANG.
　　This work was supported by the National Natural Science Foundation of China.

　　Classical strong metal-support interaction (SMSI) describes that reducible oxide migrates to the surface metal nanoparticles (NPs) to obtain metal@oxide encapsulation structure during high-temperature H2 thermal treatment, resulting in high selectivity and stability.
　　However, the encapsulation structure inhibited the adsorption and dissociation of reactant molecular over metal leading to low activity, especially for the hydrogenation reaction.
　　Recently, a research group led by Prof. LIU Yuefeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has proposed a new migration strategy, in which the TiO2 selectively migrated to second oxide support rather than the surface of metal NPs in Ru/(TiOx)MnO catalysts, boosting the CO2 reduction to CO via reverse water-gas shift reaction.
　　This study was published in Nature Catalysis on Oct. 9.
　　In-situ generation of highly efficient H-transport channel for CO2 reduction to CO（Image by Hui Kang）
　　The researchers achieved a controlled migration by utilizing the strong interaction between TiO2 and MnO in Ru/(TiOx)MnO catalysts during H2 thermal treatment, and TiO2 spontaneously re-dispersed on the MnO surface, avoiding the formation of TiOx shell on Ru NPs for the ternary catalyst (Ru/TiOx/MnO).
　　Meanwhile, high-density TiOx/MnO interfaces generated during the process, acting as a highly efficient H transportation channel with low barrier, and resulting in enhanced H-spillover for the migration of activated H species from metal Ru to support for consequent reaction.
　　The Ru/TiOx/MnO catalyst showed 3.3-fold catalytic activity for CO2 reduction to CO compared with Ru/MnO catalyst. In addition, the Ti/Mn support preparation was not sensitive to the crystalline structure and grain size of TiO2 NPs. Even the mechanical mixing of Ru/TiO2 and Ru/MnOx enhanced the activity.
　　Moreover, they verified that the synergistic effect of TiO2 and MnO didn't alter the catalytic intrinsic performance, and efficient H transport provided a large number of active sites (hydroxyl groups) for the reaction process.
　　"Our study provides references for the design of novel selective hydrogenation catalysts via the in-situ creation of oxide-oxide interfaces acting as hydrogen species transport channels," said Prof. LIU.
　　This work was supported by the NSFC of China, the Liaoning Revitalization Talents Program, the Dalian National Laboratory for Clean Energy and the AI S&T Program of Yulin Branch, the Dalian National Laboratory for Clean Energy of CAS.