Overall water splitting (OWS) using suspended particulate photocatalysts to produce green hydrogen is promising due to its cost-effective and easy large-scale application.
　　However, due to lack of inefficient cocatalysts and poor interface of cocatalyst and semiconductor, the challenging charge separation restricts the improvement of apparent quantum efficiency (AQE) under visible light.
　　Recently, a research group led by Prof. ZHANG Fuxiang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) revealed that the strong metal-support interaction (SMSI) could promote the interfacial charge separation and water oxidation activity of Ir/BiVO4 photocatalyst system, based on which they fabricated a highly-efficient redox-driven Z-scheme OWS system with a AQE of 16.9% at 420 ±10 nm under room temperature.
　　This study was published in Joule on Jan. 02.
　　The researchers obtained the Ir/BiVO4 photocatalyst with SMSI effect by high temperature hydrogen reduction treatment, and they verified that the SMSI could promote interfacial charge separation. In addition, by in-situ photoinduction, Ir species were converted into Ir and IrO2 dual-cocatalysts on the {010} and {110} facets of BiVO4, which further improved its surface catalysis and charge separation, leading the increased water oxidation performance of BiVO4 by more than 75 times.
　　On this basis, they constructed a photocatalytic Z-scheme OWS system with benchmarking AQE value of artificial photosynthesis using suspended powder photocatalyst, together with the TaON-based photocatalyst as H2-evolving photocatalyst and [Fe(CN)6]3-/4- as redox ion.
　　"This study not only extends the application of SMSI from the traditional thermal catalysis to the field of photocatalysis, but also provides a new idea for promoting photogenerated charge separation," said Prof. ZHANG.
　　This work was supported by the National Natural Science Foundation of China and the National Key R&D Program of China.

　　Recently, a research team led by Prof. LI Xianfeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a 70 kW-level high power density vanadium flow battery stack. Compared with the current 30kW-level stack, this stack has a volume power density of 130kW/m3, and the cost is reduced by 40%.
　　70 kW-level vanadium flow battery stack and its charge/discharge profile (Image by XING Feng)
　　Vanadium flow batteries are one of the preferred technologies for large-scale energy storage. At present, the initial investment of vanadium flow batteries is relatively high.
　　Stack is the core component of a vanadium flow battery. The power density determines the cost of the stack. The higher the power density is, the smaller the stack volume is, resulting in lower cost under the same power output conditions.
　　Based on self-developed highly selective weldable porous composite membranes and weldable highly conductive bipolar plates, Prof. LI's team developed a 70kW-level stack, using a short flow path, an ultra-thin battery structure, and low flow resistance and high distribution uniformity flow channels.
　　The energy efficiency of this stack is 81.0% under 70kW rated power charge and discharge conditions, and the energy efficiency is 82.1% under 60kW constant power charge and discharge conditions. In addition, the stack operates stably after more than 1,200 cycles, with only 1.7% energy efficiency decay.
　　By using this stack, a 20-foot container energy storage unit module can be upgraded from 250kW to 500kW without greatly increasing the size of power units and the cost of system-supporting facilities.
　　"This 70kW-level stack can promote the commercialization of vanadium flow batteries. We believe that the development of this stack will improve the integration of power units in energy," said Prof. LI.

　　The flavonoid xanthohumol, which is an important flavor substance in the brewing industry, has a wide variety of bioactivities.
　　However, its unstable structure is easily oxidized during the brewing process, resulting in its low content in beer. Moreover, its extraction and purification from plants requires laborious and expensive procedures, and hops cultivation is susceptible to environmental factors.
　　Recently, a research group led by Prof. ZHOU Yongjin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has proposed a microbial platform for the de novo biosynthesis of xanthohumol from glucose.
　　It can synthesize flavonoids, such as the key xanthohumol precursor demethylxanthohumol (DMX) and xanthohumol, owing to balancing the three parallel biosynthetic pathways and enhancing the prenylation efficiency by rewiring the cellular metabolism of Saccharomyces cerevisiae.
　　This study was published in Nature Communications on Jan. 4.
　　Engineering the yeast Saccharomyces cerevisiae for biosynthesis of xanthohumol by optimizing the biosynthetic pathway and rewiring the cellular metabolism (Image by ZHOU Yongjin)
　　The researchers systematically engineered the budding yeast Saccharomyces cerevisiae for an 83-fold improvement in the demethylxanthohumol (DMX) production (4 mg/L) by balancing the three parallel biosynthetic pathways, prenyltransferase engineering, enhancing precursor supply, enzyme fusion, and peroxisomal engineering.
　　Furthermore, they expressed the last methylation step produced 142 μg/L xanthohumol in shake flasks from glucose.
　　"Our work constructed a microbial cell factory for biosynthesis of xanthohumol and provided feasible approaches to optimize other complex biosynthetic pathways of natural products," said Prof. ZHOU.

　　Ethylene methoxycarbonylation reaction is the key process in the Alpha-route to produce methyl methacrylate industrially. This approach has the advantages of using widely available raw materials, having high atomic efficiency, as well as high selectivity when compared with traditional methodologies such as acetone-cyanohydrins, isobutene oxidation and ethylene hydroformylation.
　　However, ethylene methoxycarbonylation reaction still employs homogeneous Pd-P complexes as catalysts, and uses strongly corrosive acids as promoters, which has difficulty in the recovery of the catalysts and raise environmental concerns.
　　Recently, a research group led by Profs. ZHANG Tao and WANG Aiqin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) realized the ethylene methoxycarbonylation reaction over Pt1/MoS2 single-atom catalyst (SAC).
　　Pocket-like ensemble of Mo-S-Pt1-S-Mo sites for ethylene methoxycarbonylation by M-H mechanism (Image by WANG An)
　　As a bridge between homogeneous and heterogeneous catalysis, SACs are regarded as new opportunities. In this study, the researchers fabricated MoS2 nanosheets supported Pt SAC, where Pt formed multi-functional Mo-S-Pt-S-Mo entities with Mo atoms on the support.
　　They found that the metal-support concerted catalysis, Pt1/MoS2 presented good catalytic performances in ethylene methoxycarbonylation reaction under acid promoter-free conditions. The turnover frequency (TOF) reached 320 h-1, comparable to some homogeneous catalysts. Pt1/MoS2 could be reused without significant decay in catalytic activity.
　　"Our study provides a new way to design and develope efficient heterogeneous catalysts for alkoxycarbonylation reactions of alkenes," said Prof. WANG.
　　The above work was supported by the National Natural Science Foundation of China, the CAS Project for Young Scientists in Basic Research, and the National Key Projects for Fundamental Research and Development of China.

　　Strong metal-support interaction (SMSI) is one of the most important concepts in heterogeneous catalysis. Triggered by pretreatment or reaction processes, the supported metal nanoparticles may be partially or completely encapsulated by support-derived overlayers, which impact the catalytic performance of supported metal catalysts. However, the formation mechanism of the SMSI state is still unclear.
　　Recently, a research team led by Prof. FU Qiang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) proposed a gas-phase migration route for the formation of SMSI.
　　This work was published in Angewandte Chemie International Edition on Dec. 11.
　　Schematic illustration of the formation of self-limited Cu@ZnOx structure via gas-phase migration route and its effect on CO2 hydrogenation to methanol over Cu/Al2O3 catalysts (Image by SONG Tongyuan)
　　So far, two diffusion routes of the support-derived species onto the metal surface have been suggested, including interface alloying and surface migration.
　　In this work, the researchers placed ZnO particles and Cu/Al2O3 powders in a microreactor in a dual-bed mode (ZnO||Cu/Al2O3). By utilizing gas-phase migration of Zn species in CO2/H2 atmosphere (0.5% CO2/H2, 450°C), they found a self-limited thin ZnOx overlayer grew on the surface of Cu nanoparticles (Cu@ZnOx) in the Cu/Al2O3 catalyst without excessive deposition and aggregation of ZnOx species. Thus, they obtained an optimal number of ZnOx-Cu interface sites, which enhanced the methanol synthesis activity.
　　Moreover, the researchers demonstrated that the formation of the self-limited Cu@ZnOx encapsulation structure was due to the evaporation of Zn atoms from the ZnO particles, migration to the Cu/Al2O3 catalyst, and further deposition onto the Cu surface to form ZnOx overlayers under the synergistic effect of reducing H2 and oxidizing CO2 components at the treatment temperature.
　　"Our work elucidates the high temperature redox atmosphere-induced gas-phase migration route to the formation of the encapsulation structure or the classic SMSI state," said Prof. FU.
　　This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, and the Photon Science Center for Carbon Neutrality.

　　Selective hydrogenation of carbon monoxide (CO) to higher alcohols (C2+OH) is a promising non-petroleum route for producing high-value chemicals, in which precise regulations of both C-O cleavage and C-C coupling are highly essential but remain challenges.
　　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), in collaboration with Prof. WANG Ye from Xiamen University, realized highly selective CO hydrogenation to C2-4OH over a potassium-modified edge-rich molybdenum disulfide (ER-MoS2-K) catalyst.
　　This study was published in Nature Communications on Oct. 26.
　　Tunable CO hydrogenation selectivity over MoS2-based catalyst (Image by HU Jingting and WEI Zeyu)
　　The ER-MoS2-K catalyst, which was assembled in nano-array morphology with uniform linear channels, was prepared on the basis of a nano channel-confined growth mechanism.
　　The researchers found that it could deliver a high CO conversion of 17% with a superior C2-4OH selectivity of 45.2% in hydrogenated products at 240 oC and 50 bar. Moreover, by reducing the lateral size of MoS2 to enrich the edges for boosting the carbon-chain growth, the researcher achieved the C2-4OH to methanol selectivity ratio overturn from 0.4 to 2.2, and the selectivity of C2-4OH could reach to over 99% in the C2+OH products.
　　In-situ characterizations combined with theoretical calculations revealed that the sulfur vacancies (SVs) at the edge of MoS2 boosted carbon-chain growth by facilitating simultaneously the C-O cleavage of CHxO* for generating CHx* intermediate, and the subsequent C-C coupling between CO* and CHx*, while the potassium promoter promoted the desorption of alcohols via electrostatic interaction with hydroxyls, thereby enabling controllable formation of C2-4OH.
　　"This work presents the high flexibility of edge SVs of MoS2 in tailoring both C-O cleavage and C-C coupling for carbon-chain growth in CO hydrogenation, thus providing a prototype for the rational design of the nanostructure and microenvironment of active sites for selective hydrogenation reactions," said Prof. DENG.
　　This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, the Strategic Priority Research Program of CAS, and the Fundamental Research Funds for the Central Universities.