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Inverse gas chromatography (IGC) was employed in evaluating the catalytic surface of meso-microporous KIT-6 impregnated Ni (0.5–2.0 wt%) in methane dry reforming reaction. The free energy of adsorption did not changed significantly for the sample modified with highly dispersed Ni species (0.5 wt%). At higher Ni loadings, higher free energy of adsorption and enthalpy of adsorption of the probes were observed, together with high dispersive interaction and specific interaction of aromatics. The results indicated that during the impregnation, Ni species preferably penetrated into the microporous region to form Ni particles and became ‘unaccessible’. This feature was used to understand the dependence of activity on Ni loading for the gas phase catalytic methane reforming with carbon dioxide on Ni/KIT-6. The lower TOF at low metal loadings was attributed to Ni particles located in the micropores which result in diffusional constraint of reactants and products. [ABSTRACT FROM AUTHOR]

Highlights: [•] IGC was used to study surface property of MCF loaded with the sized Ni particle. [•] High adsorption free energy and heat of aromatics on MCF with ca. 5nm Ni particle. [•] Strong dispersive and specific interaction on MCF with small Ni particle (<1.4nm). [•] Ni highly dispersed on MCF promotes the great interaction with aromatics structure. [Copyright &y& Elsevier]

Abstract: The pore structure of mesoporous silica KIT-6 has been systematically tuned via the variation of calcination temperature (773–1223K), with the mesopore size ranging from 4.8 to 7.5nm and micropore volume from 0.000 to 0.078cm3/g, respectively. Four n-alkanes (C6–C9), cyclohexane, benzene, toluene, trichloroethylene, and tetrachloroethylene were employed as probe molecules in the evaluation of the pore structure effect on KIT-6 surface property using inverse gas chromatography (463.2–493.2K). High free energy of adsorption and enthalpy of adsorption were observed on the KIT-6 with the micropore volumes. The dispersive interaction parameter , and specific interaction parameter I SP, were found to decrease with the increment of the mesopore size of the samples. These results indicate that the occurrence of micropore contributes the adsorption, while the narrow mesopore of KIT-6 promotes the dispersive and specific interaction. [Copyright &y& Elsevier]

Abstract: Catalysts containing rhodium (Rh) were prepared by the wet impregnation method using H-β-zeolite as support. Retention time of three n-alkanes (C5–C7), cyclohexane, benzene, trichloroethylene and tetrachloroethylene on the Rh/H-β-zeolite catalysts (0.5–2.0wt% of Rh) and H-β-zeolite were measured by inverse gas chromatography (IGC) in the 473.2–513.2K temperature range. Standard free energy of adsorption, dispersive component of surface free energy of adsorbent and specific interaction parameters between polar probes and catalysts were evaluated. The results indicate that the adsorption characteristics of H-β-zeolite can be modified by rhodium. Surface area, enthalpy of adsorption and dispersive component of surface free energy decrease after the impregnation of rhodium. Besides, it was found that rhodium dispersed in the framework of H-β-zeolite had special adsorption for benzene which may be useful for making catalysts for certain reactions involving benzene in the future. [Copyright &y& Elsevier]

• CoMg/Al 2 O 3 was synthesized by the wetness impregnation method. • IGC was used to study the surface properties of CoMg/Al 2 O 3. • Dispersive and specific components are enhanced after Co and Mg impregnation. • CoMg/Al 2 O 3 presents high activity in aerobic oxidation of p -cresol into p -HBA. • Medium adsorption of p -cresol and strong stabilization of intermediates are involved. The surface properties of CoMg/Al 2 O 3 were evaluated in the aerobic oxidation of p -cresol. The surface interaction is enhanced greatly after Co and Mg impregnation with the mole ratio of Co/Mg from 2 : 1 and 2 : 3. The strongest interaction for the nonpolarity and benzene ring was found on CoMg/Al 2 O 3 with Co/Mg of 2 : 3. But for the interaction with p -π group bonding with negative anion, the highest value appears on the catalyst with the Co/Mg of 2 : 2. In aerobic oxidation of p -cresol, the conversion is significantly increased with Co addition and reaches around 60 % after 24 h' reaction at 338 K. The highest selectivity of p -hydroxybenzaldehyde of 99 % is achieved on Al 2 O 3 with the co-impregnation mole ratio of Co/Mg of 2 : 2. It is suggested that medium adsorption of the reactants and strong stabilization of the intermediates facilitate the aerobic oxidation of p -cresol to p -hydroxybenzaldehyde. [Display omitted] [ABSTRACT FROM AUTHOR]

Commercial fillers are widely used in the industrial manufacturing of silicone-based sealants such as CaCO 3 filled polydimethylsiloxane (PDMS). The surface property of calcium carbonate, which is readily influenced by the adsorbed water and chemical modifiers, results in different rheological performances of the composites. However, it is difficult to characterize the surface due to the multiple contributions from the morphology, functional groups, and pore structure. In this work, the surface property was differentiated by the surface energies using inverse gas chromatography (IGC). The dispersive interaction was determined by n -alkanes (C 7 -C 10), and the specific components were evaluated by cyclohexane, benzene, trichloroethylene, and tetrachloroethylene. The calcium carbonates showed the different dispersive interaction and the varied specific component on the modified surface. It was suggested that the dispersive interaction between calcium carbonate fillers and PDMS impacted the viscosity of the formed composite. [Display omitted] • Similar structure and morphology for the commercial CaCO 3 fillers. • Different DOP absorption of the fillers and varied rheology for the filled PDMS. • IGC was used to study the surface property of the modified CaCO 3. • Varied dispersive and specific components of surface energy for CaCO 3 fillers. • Strong dispersive interaction promotes the interface interaction of the composites. [ABSTRACT FROM AUTHOR]