Silica-supported 4-pyrrolidinopyridinium iodide was prepared by quaternization of 4-pyrrolidinopyridine with silica-supported alkyl iodide. The pyrrolidinopyridinium structure on the silica surface was confirmed by solid-state 13 C CP MAS NMR. The silica-supported 4-pyrrolidinopyridinium iodide showed excellent catalytic performances for transformations of various epoxides to cyclic carbonates under atmospheric pressure of carbon dioxide (CO 2 ). The reactions took place without any solvents or additives other than the catalyst. The catalyst was reusable with retention of activity and selectivity. 1-n-Hexyl-4-pyrrolidinopyridinium as a homogeneous catalyst showed a lower catalytic performance than the supported catalyst. Bifunctional catalysis involving acidic surface silanol and the basic 4-pyrrolidinopyridinium iodide was proposed.

Highly negatively charged heteropolyacids (HPAs), in particular H5BW12O40, efficiently promoted saccharification of crystalline cellulose into water‐soluble saccharides in concentrated aqueous solutions (e.g., 82 % total yield and 77 % glucose yield, based on cellulose with a 0.7 M H5BW12O40 solution); the performance was much better than those of previously reported systems with commonly utilized mineral acids (e.g., H2SO4 and HCl) and HPAs (e.g., H3PW12O40 and H4SiW12O40). Besides crystalline cellulose, the present system was applicable to the selective transformation of cellobiose, starch, and xylan to the corresponding monosaccharides such as glucose and xylose. In addition, one‐pot synthesis of levulinic acid and sorbitol directly from cellulose was realized by using concentrated HPA solutions. The present system, concentrated aqueous solutions of highly negatively charged HPAs, was further applicable to saccharification of natural (non‐purified) lignocellulose biomass, such as “rice plant straw”, “oil palm empty fruit bunch (palm EFB) fiber”, and “Japanese cedar sawdust”, giving a mixture of the corresponding water‐soluble saccharides, such as glucose (main product), galactose, mannose, xylose, arabinose, and cellobiose, in high yields (≥77 % total yields of saccharides based on holocellulose). Separation of the saccharides and H5BW12O40 was easy, and the retrieved H5BW12O40 could repeatedly be used without appreciable loss of the high performance.

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In the presence of Rh(2)(OAc)(4) (OAc = acetate) and TBA(2)WO(4) (TBA = tetra-n-butylammonium), the N-silylation of indole derivatives with hydrosilanes efficiently proceeded to give the corresponding N-silylated indoles in high yields. Pyrrole and carbazole were also N-silylated with the combined catalysts.

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Acting up with nitriles: A monovacant lacunary silicotungstate, TBA4[α‐H4SiW11O39] (I) could act as an efficient heterogeneous catalyst for dehydration of primary amides. Various kinds of primary amides, including benzylic, double bond‐containing, heteroaromatic, and aliphatic could be converted into the corresponding nitriles in moderate to excellent yields.

H ydrogen (H 2 ) is one of the most promising energy carriers and offers significant advantages, including reduction of carbon dioxide emissions at the end use and security of the global energy supply. 1 The key to realize hydrogen-based energy systems is a development of reliable materials and procedures for H 2 production, separation (sieving), storage, and sensing. Especially, much attention has been paid to the development of efficient H 2 storage materials and procedures. Among them, solid materials such as adsorbents and hydride-based materials, which can store H 2 physically (as H 2 ) or chemically (as hydride, H À ), has extensively been studied. 2,3 Polyoxometallates are a large family of well-defined anionic metalÀoxygen clusters of early transition metals and stimulated many current research activities in broad fields of science. 4 Polyoxometallates are thermally and oxidatively stable and have the following interesting redox properties: (i) abilities of reversible stepwise, multielectron redox reactions with retention of their structures and (ii) controllabilities of their redox potentials by choosing constituent elements. 5,6 In addition, heteropoly acids (HPAs, acid forms of polyoxometallates) including fully oxidized as well as reduced forms are intrinsically stable 7 and show excellent proton conductivities. 8 From the above-mentioned unique properties, we came up with an idea that HPAs can reversibly store H 2 as protons (H + ) and electrons (e À ). It is likely that the H 2 storage procedure with HPAs has the following significant advantages: (i) no need for harsh conditions for H 2 storage due to Coulombic interaction between H + and heteropolyanions, and (ii) high durability due to the stabilities of HPAs and the smaller ionic radius of H + , in comparison with H 2 , H À , and the hydrogen atom.Tungsten oxide (WO 3 ) reacts with H 2 above 673 K to form tungsten bronze. This reaction readily proceeds, even at room temperature, in the presence of noble-metal catalysts such as Pt and Pd. 9 In this case, H 2 is sorbed in the WO 3 bulk as H + and e À . 10 Recent mechanistic investigations by the groups of Georg 11 and Nakagawa 12 show that a certain amount of H 2 sorbed in WO 3 reacts with the lattice oxygen and/or O 2 , resulting in the undesirable formation of H 2 O. It has been reported that HPAs reacts with H 2 at temperatures of >520 K. Under such conditions, almost all H + formed from H 2 readily react with the lattice oxygen of HPAs to form H 2 O. 13 Although it has been reported that molybdate-based HPAs can sorb H 2 (ca. 1.0 mol mol À1 ) under mild conditions in the presence of Pd/C (Pd on activated carbon), H 2 cannot be released, because of the high stability of reduced heteropolymolybdates (see below). 14 As far as we know,

A Cs2.5H0.5PW12O40-supported platinum catalyst (Pt/CsPW) could act as an efficient heterogeneous catalyst for hydrodeoxygenation of various types of oxygen-containing compounds such as ketones, phenols, and ethers. The observed catalysis was truly heterogeneous, and the retrieved Pt/CsPW could be reused.