New research progress made by DICP scientists on hydrogen storage materials has been published recently on the journal of Chemistry of Materials ("Nanosized Co- and Ni-Catalyzed Ammonia Borane for Hydrogen Storage"(published online DOI: 10.1021/cm900672h)). The paper was cited as a highlight article by the Nature Chemistry , and was highly evaluated by the Chemistry World . This work was done by the DICP team headed by Prof. CHEN Ping.
    Ammonia borane (NH3BH3, abbreviated as AB) is regarded as the most promising hydrogen storage material due to its high hydrogen content and good stability. However, it also has the disadvantages of high hydrogen releasing temperature, volume expansion during hydrogen releasing, and the formation of by-products. The DICP team, by employing for the first time a co-precipitation method, has dispersed successfully nano-particles of Co and Ni catalysts into the AB, thus attained improvements in the hydrogen storage properties of AB, such as hydrogen release at temperatures lower than the operating temperature of PEM fuel cells, diminished volume expansion during hydrogen release, and retarding of by-product formation. These results were highly evaluated by Dr. Thomas Autrey of the National North-West Laboratory of USA, pointing out that this new hydrogen storage system may provide effective means of hydrogen supply for fuel cells.
    The whole research team of Prof. CHEN Ping was transferred to DICP from the National University of Singapore in 2008. This team has been engaging in the investigation of new hydrogen storage materials for many years. Their research accomplishments have been published in journals of Nature£¬Nature Materials£¬Angewandte Chemie International Edition and Advanced Materials .

    A DICP paper entitled "Synthesis of Thermally Stable and Highly Active Bimetallic Au-Ag Nanoparticles on Inert Supports" was published on the recent issue of the Chemistry of Materials as a cover-story paper (2009, 21, 410-418). The paper was written by Prof. ZHANG Tao and his co-workers. Before this, their another paper has already been published on ACS Chemical Communication (Chem. Comm. 2008, 3187-3189), which involved the preparation of Au-Cu catalysts supported on the SBA-15 carrier. In this newly appearing publication, the authors have extended their investigations to the Au-Ag system, and they found that incorporating of a second component of Ag or Cu could inhibit the sintering of the gold nano-particles during high temperature calcination, thus developed a general method for the preparation of highly active and thermally stable nano-Au catalysts .
    The DICP team headed by Prof. Zhang Tao has been engaging in the R&D of new generations of highly efficient catalysts for utilization in the attitude control devices of space vehicles, such as catalysts for the decomposition of hydrazine. For spacecraft applications, the catalysts have to be highly dispersed and sinter-proof, and the new findings of this research team have provided useful guidelines for the preparation of new generations of spacecraft catalysts with lower costs and better performances.

    The results of the investigation on the topological effect of nano-catalysts accomplished by the DICP research team headed by Prof. SHEN Wenjie was published in the journal of Nature (458 (2009) 746-749) appeared on 9th April. In this study, through a delicate control of the size and topology of the nano-scale catalytic particles of metal oxides, it was possible to overcome the hindering of existing water vapor and to realize the reaction of low temperature CO oxidation over non-precious metal oxide catalysts. These results have significance in the development of catalysts for vehicle exhaust emissions and for other environmental protection applications.
    The key points of the DICP results comprised the successful preparation of highly structure-ordered nano-rods of Co3O4, in which the (110) crystal plane constituted 40% of the nano-rod surface. These Co3O4 particles were the active sites for CO oxidation, they could realize a complete oxidation of CO at a temperature as low as -77 degrees Centigrade in the presence of moisture, and the reaction rate was 10 times higher than those of the conventional Co3O4 catalysts.
    In this issue of the Nature , an interview with Prof. SHEN Wenjie has also been published.

    The DICP research team headed by Prof. ZHANG Tao and in collaboration with Prof. Jingguang Chen of the Delaware University, USA, has accomplished a research paper entitled "Direct Catalytic Conversion of Cellulose into Ethylene Glycol Using Nickel-Promoted Tungsten Carbide Catalysts", which has been published as a cover-paper in the Angew. Chem. Int. Ed. recently ( Angew. Chem. Int. Ed. 2008, 47, 8510 - 8513 ).
    Cellulose is one of the most abundant bio-mass resources in nature, and due to its non-edible characteristics, large scale utilization of this material as energy or chemical resources will not give rise to a negative effect on world-wide foodstuff supply. Accordingly, cellulose is regarded as a promising source for manufacturing sustainable energy supply and organic chemicals. However, cellulose is also one of the most difficultly hydrolyzed substances, which is generally treated conventionally first with liquid acids, alkalis or enzymes to convert it into glucose, then further transform the glucose into some forms of energy or chemicals. These traditional processes are usually tedious and polluting. In recent years, researchers have tried to convert cellulose in the presence of noble-metal catalysts into hexa-basic alcohols, and this is regarded as a green approach. However, the rather low selectivity of the process as well as the high cost of the noble-metal catalysts has hindered commercial application of this approach.
    In the DICP work, by considering the noble-metal-like properties of tungsten carbides, the investigators tried for the first time to use low-cost tungsten carbide catalysts for the conversion of cellulose into polybasic alcohols. They found that tungsten carbide, when supported on an activated carbon carrier, not only could transform cellulose into polyols, but also exhibited an extra high selectivity to glycol. Especially, when small amount of nickel was added as a promoter, the selectivity to glycol could be as high as 61%. Glycol, usually manufactured from petroleum feedstuffs, is a widely used raw material, and is increasing
    in the rate of 5% per year. These results of the DICP investigation might open up a new route for producing glycol from bio-masses instead of petroleum resources, thus attracting the attentions of the glycol-manufacturing companies as well as the news media.

    Non-adiabatic processes of molecular systems are quite common phenomena in the nature, but they are very difficult research topics both experimentally and theoretically. DICP scientists and their collaborators have made important progress in the studies of the non-adiabatic kinetics of the Cl + H2 reaction, thus solving a problem of great controversy in the field of chemical kinetics. The results were published in the journal of Science appearing on 24th October, and was cited by the Chemical & Engineering News of 27th October.
    The reactivity of the spin-orbital excited states of the chlorine atom is a hot topic in research work. Previously, researchers have found experimentally that even under very high collision energies, the reactivity of the spin-orbital excited states of the chlorine atom is much higher than that of the ground state, and these findings are in conflict with the most precise theoretical derivations. Accordingly, this discrepancy constitutes a great challenge to the effectiveness of the Born-Oppenheimer approximation.
    The DICP research team, headed by Prof. YANG Xueming, determined the relative differential cross sections of the ground state and the excited states of the Cl + H2 reaction by means of a Rydberg state hydrogen time of flight mass spectrometer ¨C cross molecular beam installation, and found that under low collision energies, the reactivity of the spin-orbital excited state of the chlorine atom was comparative to that of the ground state, and this implied that the Born-Oppenheimer approximation is not effective in this reaction at low collision energies. However, as the collision energy was increased, the reactivity of the spin-orbital excited states of the chlorine atom became smaller and smaller as compared to that of the ground state, implying that the Born-Oppenheimer approximation was effective under high collision energies.
    Meanwhile, detailed theoretical results obtained via complete quantum scattering kinetic calculations for this reaction system by Prof. ZHANG Donghui of DICP, in collaboration with Prof. XIE Daiqian of the Nanjing University and Prof. Millard H. Alexander of the Maryland University, USA, were in good consistency with the experimental results mentioned above. This also implies that theoretical studies in three-atom non-adiabatic kinetics have attained a very high precision.

    The studies of gold-copper catalysts conducted by a DICP research team and published in the journal of Chemical Communications (LIU Xiaoyan, WANG Aiqin, ZHANG Tao, et. al, Chem. Comm. , 2008, 3187-3189) has been estimated as a Research Highlight article by the NATURE (China) web.
    In this work, the DICP researchers, by making use of the channel limiting effect of the ordered mesopores of SAB-15 zeolites, and combining with the easily functionalizing properties of the zeolite walls, have prepared successfully highly thermo-stable and well dispersed Au-Cu nano-sized alloys inside the zeolite channels. The alloy particles had a homogeneous size of ca. 3nm. This kind of catalysts showed high activities for CO selective oxidation under an oxygen-rich atmosphere due to the synergistic effect between the gold and copper particles.
    Heterogeneous catalysis via nano-sized metal particles is a hot research topic in recent years. This DICP research team, headed by Prof. ZHANG Tao, has been engaging in the investigations of highly efficient supported catalysts through the modifying and controlling of the particles sizes of the active components, especially catalysts aiming at space-technology applications. Up to now, they have developed novel catalyst systems by means of the above mentioned techniques, such as ordered activated carbon-supported iridium catalysts ( Chem. Mater. 2008, 20, 1881¨C1888£©and nano-sized molybdenum carbide catalysts( Chem. Commun. , 2008, 2565¨C2567).

    The DICP research team headed by Prof. TIAN Zhijian has proved recently that water plays a very important role in the synthesis of zeolites, and their results were published in the Journal of American Chemical Society (J. Am. Chem. Soc. 2008, 130: 8120-8121).
    Usually water exists in a large amount during the synthesis process of zeolites, so it is very difficult to understand clearly the role of water in the course of crystallization of zeolites. In their studies, the DICP team employed innovatively completely water-free pseudoboehmite(AlOOH), dihydroammonium phosphate(NH4H2PO4) and ammonium fluoride(NH4F) as the raw materials for the thermal synthesis of zeolites, such that they could control the amount of water added in a quantitative way. They have found that when no water was added externally, the zeolites only crystallized very slowly in the presence of a trace of water produced by the reacting system itself. However, if a stoichiometric amount of water (H2O/Al=1, mole ratio) was introduced, the crystallization rate of the zeolites was very greatly enhanced. This proved that the crystallization process during zeolite synthesis follows an autocatalyzed mechanism, and the addition of stoichiometric quantity of water or other polar substances can accelerate the crystallization rate drastically. Their paper has been highly evaluated by the four referees, who remarked that "this has confirmed clearly for the first time the high sensitivity of water content to the formation of zeolites."
    This research program was financially supported by the National Natural Science Fund of China as well as a grant from SINOPEC. In recent years, this research team has been engaging in the investigations of new methods as well as mechanisms of zeolite synthesis. They have reported for the first time thermo-ionic synthesis of zeolites via microwave promotion(Angew. Chem., Int. Ed., 2006, 45: 3965-3970), and they also discovered the unique structure-templating role of organic amines during the ionic thermal synthesis of zeolites(J. Am. Chem. Soc., 2006, 128: 7432-7433).

    The DICP research team headed by Prof. YU Zhengkun has made important progress in the study of controlling and rearranging of transition metal catalysts, and their results have been published in the newly appeared Journal of American Chemical Society(J. Am. Chem. Soc. 2008, 130, 8136-8137).
    Activation of inert C-H bonds on transition metal catalysts is a hot topic in catalysis studies. The new exploration of the DICP team involved the utilizing of inexpensive acyl chloride as the coupling agent for transition rhodium complex catalysts, and with 4A zeolite as a promoter. This kind of new catalyst system can catalyze the decarbonylation-coupling reaction of ortho-substituted pyridyl-aromatics under mild conditions, with the simultaneous and highly selective formation of new carbon-carbon bonds. This has evidenced for the first time a convenient and low-cost route for the formation of carbon-carbon bonds via the activation of C-H bonds.

    A basic research paper entitled "HF(v'=3) forward scattering in the F+H2 reaction: Shape resonance and slow-down mechanism" has appeared in the recently published journal PNAS (Proceedings of National Academy of Sciences) of USA [Vol. 105,6227-6231(2008)]. The paper was written by Prof. YANG Xueming, Prof. ZHANG Donghui and coworkers.
    The mechanism for the formation of the forward scattering of the HF(v'=3) product in the F + H2 reaction has puzzled the chemical dynamics researchers for more than 20 years. The phenomenon of the above mentioned forward scattering of the HF(v'=3) product was first observed by Y.T. Lee and co-workers in the 1980's. They have speculated that this is due to the resonance states of reaction. However, research outcomes of the 1990's did not give support to their speculation. Recently, the research team headed by Prof. YANG Xueming of DICP has succeeded in determining full quantum state resolved spectra of the F+H2 -> HF(v'=3)+H reaction by means of a custom-made cross molecular beam-H atom Rydberg tagging time-of-flight installation. On the other hand, theoretical analysis basing on the potential surface for this reaction, constructed by Prof. ZHANG Donghui of DICP and Prof. XU Xin of Xiamen University, showed that the forward scattering of the HF(v'=3) product is resulted from a time lagging effect due to the slowing down of the product when it is passing over the centrifuge potential of the HF(v'=3) adiabatic vibration potential. Thus, the combination of highly sophisticated experiments with a precise theoretical analysis has given a clear answer to the long standing puzzle in chemical dynamic studies.

    After the successful realization of selective oxidation of methane to methanol at a low temperature(80⁰C) via the constructing of the multi-pairs electrons circulation system ( J. Am. Chem. Soc. , 128(2006) 16028), the DICP research team headed by Prof. BAO Xinhe has attained another new progress in basic studies of methane direct activation. By collaborating with the National West Pacific Laboratory of USA, they obtained information on the intact structures of active centers of solid catalysts. This accomplishment was achieved by applying the High Field Solid Nuclear Magnetic Resonance technique for the investigation of practical catalyst systems. The results of their studies were published in the newest issue of JACS ( J. Am. Chem. Soc.z , 130(2008)3722). An abstract of the paper also appeared in the recently published Chemical & Engineering News (C&E News) .
    In this work, the molybdenum(Mo) species on the surface of the catalyst were observed directly with the 95Mo NMR technique. The DICP researchers found that during the preparation processes of the Mo/ZSM-5 catalysts, strong interaction would occur between the Mo species and the acidic sites of the ZSM-5 support, forming a kind of Mo-O-Al moiety. Moreover, this strongly interacting moiety was in equilibrium with the molybdenum oxide crystallites which were existing under a weak interaction state. It was revealed that the surface Mo-O-Al species were predominant if the Mo loading on the catalyst was high, while the molybdenum oxide crystallites were prevailing when the Mo concentration was low. By correlating with catalytic reaction results, it was concluded that those Mo-O-Al species locating on the exchangeable sites were the active centers for reactions of methane direct conversions.
    This was the first successful attempt in utilizing the High Field 95Mo NMR technique for the investigation of practical catalysts, manifesting the great potentiality of utilizing the High Field NMR technique in solving chemical problems concerning atomic nuclei like molybdenum, silver and titanium, which are difficult to tackle by traditional means.

      Propylene oxide has an estimated worldwide production of about 4.5million metric tons per year valued at about $6 billion. It is used in the manufacture of polyurethane, propylene glycols, and other products. A considerable amount of propylene oxide is still produced via the chlorohydrin route despite a large consumption of Cl2 and the environmental impact of this method. Therefore, tremendous research efforts have focused on the development of homogeneous and heterogeneous catalysis for epoxidation of olefins. A highlight is the reaction-controlled phase-transfer catalysis developed by Professor Xi and co-workers in Dalian Institute of chemical Physics, Chinese academy of science [Science, 292, 1139 (2001)].
      The epoxidation of olefins with H2O2 was performed with a tungsten-containing catalyst. This insoluble catalyst forms soluble active species by the action of H2O2, and when the H2O2 is used up, the catalyst precipitates for easy recycling. Thus, the advantages of both homogeneous and heterogeneous catalysts are combined in one system through reaction-controlled phase transfer of the catalyst. When coupled with the 2-ethylanthraquinone/2-ethylanthrahydro- quinone redox process for H2O2 production, O2 can be used for the epoxidation of propylene to propylene oxide with 85% yield based on 2-ethylanthrahydroquinone without any co-products. This approach avoids the problematic co-products normally associated with the industrial production of propylene oxide.
      A comment paper from Chemical & Engineering News on this paper [May 14, 2001, Volume 79, Number 20, pp. 15] said a tungsten catalyst system developed by a team of researchers in China holds promise for a more economical and environmentally friendly route to production of propylene.
      A comment paper in chemistry of Nature online [15 May 2001] said reaction-controlled phase-transfer catalysts maximize the yield of a reaction while keeping the catalyst easily separable from the reaction mixture.