The world’s first project to industrially synthesize 25 kt/a of higher alcohols from syngas passed a continuous 72-hour catalyst performance test on 3rd November, 2019 in Yulin, Shaanxi province, china.
　　The project, developed by researchers from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, offers a new method for directly synthesizing high value-added fine chemicals from syngas and suggests new ways to cleanly convert and utilize coal resources.
　　Results of the catalyst test showed that at 30% of catalyst loading, total conversion of syngas exceeded 84%; selectivity of methane was less than 6%; and selectivity of alcohols/aldehydes/olefins exceeded 60%.
　　Higher alcohols – the key products of this process – are often used as intermediates in the synthesis of plasticizers, detergents and lubricants, and are generally produced through the Ziegler and Oxo processes. However, these processes involve drawbacks, such as cumbersome steps as well as the use of dangerous catalysts in the Ziegler process.
　　DICP scientists and their collaborators have been conducting basic research and industrial testing on high-selectivity production of higher alcohols from syngas over Co-based catalysts since 2004. As part of their research, they designed a series of novel Co-based catalysts, namely, activated carbon supported Co-Co2C catalysts. The active site of these catalysts is supposed to be the interfacial sites between metallic Co and cobalt carbide (Co2C).
　　The researchers also proposed the mechanism by which alcohols are formed on the interfacial sites between Co and the Co2C sites. That is, CO molecules are associatively adsorbed on the surface of the Co2C sites and then inserted into the alkyl chain formed on the adjacent metallic Co sites.
　　The new catalytic method may make Fischer-Tropsch synthesis (FTS) more practical. FTS is one of the most versatile processes for converting syngas (CO+H2) derived from coal, natural gas, and biomass into various chemical products. FTS is notable for producing high-quality paraffins. In addition, using FTS to directly synthesize olefins and oxygenates (mainly linear α- alcohols) from syngas is a promising “one-pot-one-step” method due to the high added-value and large potential demand for these olefin and oxygenate products. However, no catalytic system has performed sufficiently well for industrial implementation to date.
　　The results of the current catalyst test suggest that the direct conversion of syngas into high value-added fine chemicals can now be accomplished at industrial scale, thus suggesting many more opportunities for cleanly and efficiently utilizing coal resources.(Text by ZHAO Ziang）

　　Recently, the research group led by Prof. DING Yunjie from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Scientists (CAS) has developed a universal and easily scale-up strategy to atomic dispersed from activated carbon supported noble metal nanoparticles, which was published in Nature Communication.
　　Supported noble metal catalysts have been used broadly in heterogeneous catalysis, and the catalyst deactivation often occurred due to sintering and agglomeration. Scientists have developed many methods to reverse this process, including oxidation and reduction, chlorination and oxychlorination, thermal treatment with halohydrocarbons.
　　However, many disadvantages still existed for these methods. The dispersion of nanoparticles (NPs) cannot reach to the atomic level own to the limitation of Ostwald Ripping, the operation conditions are rather harsh and rigorous, often needing very high temperature and one method usually concentrated on a single metal.
　　In this work, noble metal nanoparticles of Rh, Ir, Pt, Pd, Ru and Ag with 5 wt% loading supported on activated carbon (AC) can be completely dispersed into stable mononuclear complex through the thermal treatment of CO and CH3I. The dispersive process and mechanism are discussed detailed in the case of Rh metal as an example. It is found that the Rh NPs supported on AC could be efficiently transferred into the stable mononuclear complexes of Rh(CO)2I3(O-AC) and Rh(CO)I4(O-AC), in which O-AC represent the oxygen-containing groups on the surface of AC.
　　The combined action of proper temperature, CO, CH3I and the oxygen-containing groups on the surface of AC are indispensable for the atomic dispersion of supported NPs. Hemolytic cleavage of CH3I on the surface of Rh NPs produces large amount of free radicals (I·). The synergetic effect of CO and I· promotes the breakage of Rh-Rh bond and the formation of mononuclear complexes, leading to the gradual dispersion and decrease Rh NPs. The O-AC provides the anchoring site for the detached mononuclear complexes.
　　The dispersive process of nanoparticles through the thermal treatment of CO and CH3I mixture. (Image by FENG Siquan)
　　This work shares a universal and simple strategy to regenerate the sintered catalyst and to synthesize supported mononuclear complexes of most precious metal. It will bring about new insights and points for the design of single-metal-site catalyst. This work was supported by National Key R&D Program of China (2017YFB0602203) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA21020300 and XDB17020400). (Text and image by SONG Xiangen and FENG Siquan).
　　

Recently, the research group led by Profs. ZHANG Tao and WANG Aiqin from the Dalian Institute of Chemical Physics (DICP), the Chinese Academy of Sciences reviewed the advances in selective hydrogenation reactions catalyzed by nano- and single-atom catalysts. The review was published in Chemical Reviews. Selective hydrogenation refers to when two (or more) reducible functional groups co-exist in the reactants, the targeted one is saturated whereas the other remains intact. Selective hydrogenation reactions have wide applications in both petrochemical and fine chemical industries. However, it remains a great challenge because of the various side reactions (e.g., over-hydrogenation) on traditional nano-catalysts.
　　Chronological development of nano- and single atom catalysts for the selective hydrogenation reaction of alkynes, nitrostyrenes, and α,β-unsaturated aldehydes/ketones. (Image by ZHANG Leilei) Experimental and theoretical calculation results revealed that when the ensemble of active metal is reduced, the adsorption of the untargeted group is weakened, by which the chemoselectivity can be greatly improved. Accordingly, the “active site isolation” strategy is proposed to achieve high selectivity in hydrogenation reactions. This review summarized the approaches towards the site isolation, including adsorption/grafting of N/S/P-containing organic molecules on the metal surface, partial covering of active metal surface by metal oxides either via doping or through strong metal-support interaction, confinement of active metal nanoparticles in micro- or meso-pores of the supports, and construction of single-atom catalysts on reducible oxides or inert metals. Both advantages and disadvantages of each approach have been discussed for three types of chemoselective hydrogenation reactions, including alkynes/dienes to monoenes, α,β-unsaturated aldehydes/ketones to the unsaturated alcohols, and substituted nitroarenes to the corresponding anilines. Finally, the development directions in this area were prospected, and some advices were put forward. This work was supported by the National Key Projects for Fundamental Research and Development of China, the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences. It was dedicated to the 70th anniversary of DICP, CAS. (Text and image by ZHANG Leilei)

　　A research group led by Prof. LIU Shengzhong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), and Prof. YANG Dong at Shaanxi Normal University developed the high efficiency semi-transparent perovskite solar cells by using MoO3 sandwiched gold nanomesh (MoO3/Au/MoO3) multilayer as the transparent electrode. Combined with a superior heterojunction silicon solar cell, a high efficiency four-terminal perovskite/silicon tandem solar cell was obtained. Their findings were published in Advanced Functional Materials.
　　 The top image is the device structure of the semi-transparent perovskite cell with ultra-thin gold nanonet as transparent electrode. The left image is the photograph of the semi-transparent device. The right image shows the J-V characteristic of the semitransparent perovskite top cell (red line) , the silicon bottom cell (blue line) and the silicon cell works indepently (black line).（Image by DUAN Lianjie, WANG Ziyu）
　　The crystalline Si-based solar cells have been dominating the ever-expanding global photovoltaic (PV) market with about 95% market share. With its highest cell efficiency of 26.6% reaching its theoretical limit, there is little hope to further raise its performance by just device optimization within the single-junction cell architecture.
　　Tandem/multijunction structure was proven to be an effective way to break the Shockley-Queisser limit. To obtain a high efficiency tandem solar cell, a key of merit thing is to fabricate transparent electrode with high cinductivity as well as high transparency using a mild mrthod.
　　To obtain the high conductive and high transparent transparent electrode, the group demonstrated a MoO3/Au/MoO3 multilayer fabricated by thermal evaporation. The thermal evaporation is mild that could not damage the underneath layer.
　　The large surface tension of MoO3 effectively improves wettability for gold, resulting in Frank–van der Merwe growth to produce an ultrathin gold nanomesh layer, which guarantees not only excellent conductivity but also great optical transparency. The top MoO3 layer reduces the reflection at the gold layer to further increase light transmission.
　　As a result, the semitransparent perovskite cell shows an 18.3% efficiency, the highest reported for this type of devices. When the semitransparent perovskite device is mechanically stacked with a heterojunction silicon solar cell of 23.3% PCE, it yields a combined efficiency of 27.0%, higher than those of both the sub-cells. This breakthrough in elevating the efficiency of semitransparent and multijunction/tandem devices can help to break the Shockley–Queisser limit.
　　The research was supported by the National Natural Science Foundation of China, National Key Research and Development Program of China, Shaanxi Technical Innovation Guidance Project, the 111 Project. (Text/Image by DUAN Lianjie, WANG Ziyu)

　　Scientists from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Scientists (CAS), collaborated with the National University of Singapore, Kyoto University, and Hokkaido University have developed a strategy to stabilize isolated metal atoms on various oxide supports by using ionic liquids (ILs) as an electronic stabilizer. Their findings were published in Chem.
　　Supported single-atom catalysts (SACs) have emerged as a new frontier in heterogeneous catalysis and have attracted broad interest for their demonstrated good catalytic performance due to high atomic efficiency and relatively homogeneous active sites.
　　Strategies have been developed to fabricate various SACs. However, how to effectively stabilize these SACs remains challenging as singly dispersed isolated atoms tend to aggregate into thermodynamically more stable nanoparticles (NPs).
　　The scientists investigated the effect of common ILs on stabilizing single-atom Pt1 and Pd1 on several supports. The ILs-stabilized SAC (ILSSAC) 0.2Pt/HAP (hydroxyapatite) was first selected as an example to systematically characterize the dispersion state of Pt before and after the hydrogenation reaction, and to quantify the electrostatic stabilization effect of ILs on single-atom Pt using density functional theory (DFT) calculations.
　　Afterwards, the strategy was extended to Pt1 catalysts dispersed on various supports and single-atom Pd1 catalysts loaded on HAP to prove the general applicability of the strategy.
　　"The results showed that the introduction of ionic liquids as a stabilizer not only effectively stabilizes single-atom Pt1 and Pd1 on Ca10(PO4)6(OH)2 (HAP) and other oxide supports, but also improves their catalytic performance," said QIAO Botao, a researcher from DICP. 
　　Scheme illustration of the preparation of SACs and the stabilization by Ils. (Image by DING Shipeng)
　　The acetylene conversion and ethylene selectivity over 0.02Pd1/HAP and BmimBF4-0.02Pd1/HAP catalysts at 90 °C and 100 °C, respectively. (Image by DING Shipeng)
　　Considering that the physicochemical properties of ILs can be easily finetuned by the rational control of cations and anions, ILs stabilization is a simple strategy for enhancing the stability of a broad range of single-atom catalysts already reported in the literature or under development in various labs.(Text by GUO Yalin, image by DING Shipeng)

　　A research team led by Prof. YANG Xueming from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences reviewed the progress of Single Molecule Photocatalysis on TiO2 Surfaces. The article was published in Chemical Reviews.
　　 
　　STM images of the photolysis of H2O monomer, dimer, trimer and tetramer on R-TiO2(110) under 266 nm irradiation (Image by GUO Qing)
　　Heterogeneous photocatalysis has been widely applied in various fields, such as photovoltaic cell, solar water splitting, photocatalytic pollutant degradation, and so on. Therefore, the reaction mechanisms involved in these important photocatalytic processes, especially in TiO2 photocatalysis, have been extensively investigated by various surface science techniques in the past decade.
　　In this review, Scientists summarized the recent progress that provides fundamental insights into TiO2 photocatalysis through direct tracking the evolution of single molecule photochemistry on TiO2 single crystal surfaces using a combination of scanning tunneling microscopy (STM) and other surface science techniques.
　　The details of the single molecule photocatalysis of several important molecules (water, alcohols, and aldehydes) on the model TiO2 surfaces were highlighted, and perspectives on single molecule photocatalysis on TiO2 surfaces in the future were provided.
　　The above work was supported was supported by the National Natural Science Foundation of China (NSFC Center for Chemical Dynamics, 21673235), the Strategic Priority Research Program of Chinese Academy of Sciences (XDB17000000), and the Youth Innovation Promotion Association CAS (Text by GUO Qing)