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A Pd/SiO2@S1@H‐ZSM‐5 capsule catalyst (Pd/SiO2–SZ) is fabricated through a dual‐layer crystal growth method with an auxiliary hydrothermal reaction. The catalyst exhibits excellent selectivity to liquefied petroleum gas (LPG) in CO2 hydrogenation reactions, which is attributed to the tandem reactions of methanol synthesis on the Pd/SiO2 core catalyst and methanol dehydration to hydrocarbons on the H‐ZSM‐5 shell. The Pd/SiO2–SZ capsule catalyst has a similar mesoporous structure, narrow range of Pd particles size distribution, and consistent reduction characteristics to the Pd/SiO2 core catalyst. It maintains the physical and chemical properties of the core catalyst throughout the H‐ZSM‐5 shell synthesis process. Energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy results reveal that the H‐ZSM‐5 zeolite shell completely encapsulates the Pd/SiO2 core catalyst. Compared with the crushed capsule catalyst (Pd/SiO2–SZP), the well‐defined‐structured Pd/SiO2–SZ catalyst has a much higher LPG selectivity of 33.6 %, owing to the well‐matched reactions at the Pd/SiO2 core and H‐ZSM‐5 shell. [ABSTRACT FROM AUTHOR]

Abstract: A zeolite capsule catalyst Cr/ZnO–S–Z was prepared successfully by a novel dual-layer method, in which one layer of neutral Silicalite-1 zeolite shell was first synthesized on the bimetallic Cr/ZnO core catalyst, acting as the intermediate layer for the following H-type H-ZSM-5 zeolite shell direct synthesis on its surface. By using this dual-layer method, it can be easily realized that the formation of H-ZSM-5 zeolite membrane on the millimeter-sized bimetallic substrates. Direct synthesis of dimethyl ether (DME) from syngas at higher reaction temperature was the application of this zeolite capsule catalyst to test its catalytic performance. In reaction, this zeolite capsule catalyst could realize the exactly controlled synthesis of DME, suppressing the formation of other alkane/alkene by-products simultaneously, demonstrating its exclusive ability for the selective synthesis of target product compared with the conventional hybrid catalyst. [Copyright &y& Elsevier]

The thermal decomposition of synthetic serrabrancaite (MnPO4 · H2O) was studied in N2 atmosphere using TG-DTG-DTA. Thermal analysis results indicate that the decomposition occurs in two stages, which are assigned to the dehydration and the reduction processes and the final product is Mn2P2O7. X-ray powder diffraction, FT-IR and FT-Raman techniques were used for identification of the solid decomposition product. The decomposition kinetics analysis of MnPO4 · H2O was performed under non-isothermal condition through isoconversional methods of Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS). The dependences of activation energies on the extent of conversions are observed in the dehydration and the reduction reactions, which could be concluded the “multi-step” processes. [ABSTRACT FROM AUTHOR]

Abstract: A new binary Co1/2Fe1/2(H2PO4)2·2H2O was synthesized by a simple, rapid and cost-effective method using CoCO3–Fe(c)–H3PO4 system at ambient temperature. Thermal treatment of the obtained Co1/2Fe1/2(H2PO4)2·2H2O at 600°C yielded as a binary cobalt iron cyclotetraphosphate CoFeP4O12. The FTIR and XRD results of the synthesized Co1/2Fe1/2(H2PO4)2·2H2O and its final decomposed product CoFeP4O12 indicate the monoclinic phases with space group P21/n and C2/c, respectively. The particle morphologies of both binary metal compounds appear the flower-like microparticle shapes. Room temperature magnetization results show novel superparamagnetic behaviors of the Co1/2Fe1/2(H2PO4)2·2H2O and its final decomposed product CoFeP4O12, having no hysteresis loops in the range of ±10,000Oe with the specific magnetization values of 0.045 and 12.502emu/g at 10kOe, respectively. The dominant physical properties of the obtained binary metal compounds (Co1/2Fe1/2(H2PO4)2·2H2O and CoFeP4O12) are compared with the single compounds (M(H2PO4)2·2H2O and M2P4O12; where M=Co, Fe), indicating the presence of Co ions in substitution position of Fe ions. [Copyright &y& Elsevier]

Abstract: A new binary cobalt iron cyclotetraphosphate, CoFeP4O12 was synthesized through solid phase reaction using cobalt carbonate, iron metal and phosphoric acid in the presence of water–acetone media with further calcinations at the temperature of 500°C. The particle size obtained from X-ray line broadening is 65±24nm for the CoFeP4O12. FTIR spectrum of CoFeP4O12 is assigned based on the P4O12 4− ion in the structure. The SEM micrograph of the synthesized CoFeP4O12 shows non-uniform microparticle, which is important for specific application. Room temperature magnetization result shows superparamagnetic behavior of the CoFeP4O12 powder, having no hysteresis loop in the range of ±10,000Oe with the specific magnetization value of 14.243emu/g. The XRD and FTIR results of the synthesized CoFeP4O12 appear to be very similar to that of M2P4O12 (M=Co and Fe), which indicates the monoclinic phase with space group C2/c. [Copyright &y& Elsevier]