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Synthesizing fine chemicals and valuable pharmaceutical intermediates through selective catalytic oxidation of alcohols is indispensable and crucial. However, the conventional methods of alcohol oxidation have inevitable drawbacks, including harsh reaction conditions and environmental pollution. Thus, it is imperative to develop efficient catalytic oxidation systems for alcohols. Herein, we successfully synthesized a 15 wt %PI‐TiO2 composite by a one‐step solid‐state heating polymerization technique. This catalyst exhibits excellent responsiveness to visible light and demonstrates remarkable catalytic activity. Furthermore, TEMPO was introduced as a cocatalyst to construct a PI‐TiO2/TEMPO/O2 system for the catalytic oxidation of alcohols. In comparison to the individual effects of PI or TiO2, this system showcases improved catalytic activity and broader substrate applicability. As a result, the conversion efficiency of benzyl alcohol increases by 3.44 times and 2.26 times, respectively. This research not only introduces a novel approach for preparing visible light‐active PI‐TiO2 catalysts but also indicates the significance of establishing an efficient electron transfer process in alcohol catalytic oxidation. [ABSTRACT FROM AUTHOR]

A series of core‐shell catalysts with different shell thickness were synthesized and the effect of microporous silica shell on product distribution of Fischer‐Tropsch synthesis was analyzed. Fe3O4 core was prepared by hydrothermal method and the amorphous SiO2 shell was coated on the Fe3O4 core by sol‐gel method. N2 adsorption‐desorption analysis indicated an irregular and microporous silica shell and the pore size distribution moved to smaller diameter with the shell thickness increased. In Fischer‐Tropsch synthesis, inactive silica shell increased catalytic activity (FTY) and stability by restricting catalyst cracking and sintering. Product distribution shifted to C1‐C4 gaseous hydrocarbons with the increasing shell thickness probably due to the diffusion limitations on reactants/products and structure confinement and separation effect of microporous silica shell on restricting the growth of catalytic active particles. Selectivities of C5+ were restricted within 10% for core‐shell catalysts. WGS reaction activity is reduced as well, which constrains side reaction and amplifies FTS catalytic productivity to hydrocarbons. Fe3O4 nanospheres coated with microporous silica shell catalyst inhibits carbon chain growth and shifts FTS product distribution to gaseous hydrocarbons (C1‐C4). The inactive silica shell separates neighboring actives sites of iron core and inhibits the growth of iron carbides also confined carbon chain growth. Catalytic activity and stability are enhanced and water‐gas shift reaction activity is reduced and hydrocarbon productivity is improved over core‐shell catalysts. [ABSTRACT FROM AUTHOR]

5‐hydroxymethylfurfural (HMF), an important platform compound produced from lignocellulosic biomass, is widely applied in petrochemical industry for downstream synthesis of medical supplies or intermediate of the other important chemicals by the typical catalytic processes. A continuous production route was developed to yield HMF from monosaccharides by using zirconium phosphate (ZrP) with different Zr/P ratios as catalysts. Its physicochemical properties were then characterized by Brunauer‐Emmett‐Teller (BET), X‐ray powder diffraction (XRD), X‐ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT‐IR), pyridine adsorbed Fourier transform infrared spectroscopy (Py‐FT‐IR), X‐ray fluorescence (XRF) and temperature programmed desorption of ammonia (NH3‐TPD) techniques. A mixed phase containing monosaccharide in aqueous and dimethyl sulfoxide (DMSO) phase was applied in the fixed bed to keep the continuous production. The optimized reaction conditions were applied to maximized HMF yield by varying the processing parameters. The highest HMF yield of 56.3% was obtained when using fructose as the feedstock under the reaction condition of 120 °C, 180 min, N2 pressure 2 MPa and DMSO: fructose solution of 9:1 over ZrP with the P/Zr with molar ratio of 2. Comparatively, the glucose conversion of 72% with the HMF yield of 32% were gained under the same conditions using glucose as the feedstock. It is deduced that the ZrP catalysts simultaneously possessing Brönsted/Lewis acid showed synergy in glucose dehydration to HMF. The ZrP catalyst showed good stability and no obvious deactivation was observed after 30 h of time‐on‐stream, due to the primary structure and acidic properties of catalyst can be kept during the reaction. Finally, it is generally efficient for some C6 sugars dehydration to HMF with the Brönsted/Lewis acid synergy of ZrP. ZrP solid acids synthesized with dfferent Zr/P ration are tested in the dehydration of typical C6 monosaccharides to HMF (5‐hydroxymethylfurfural). ZrP (P/Zr = 2) showed the best catalytic activity for obtaining the highest HMF yield of 56.3%. The ZrP catalyst is generally efficient for C6 sugars dehydration to HMF, where B and L acidic sites showed synergism effect on glucose dehydration to HMF. [ABSTRACT FROM AUTHOR]

Sorbitol, as a C6 sugar related compound derived from cellulose, is regarded as a promising biomass‐derived substrate and has characteristically higher oxygen content than in fossil‐based resources. In this work, ruthenium–molybdenum carbon catalysts prepared by different impregnation processes were employed and extensively studied in a trickle‐bed reactor for sorbitol hydrodeoxygenation (HDO). Interestingly, these catalysts afforded remarkably different HDO performance. Ruthenium–molybdenum catalysts prepared by ultrasonic treatment and calcination obtained high HDO performance in sorbitol conversion with 79.8 % carbon yield of C5/C6 alkanes (pentane and hexane), almost twice that of ruthenium–molybdenum catalysts prepared without using a calcination processes. Therefore, a series of characterization studies (N2‐adsorption, XRD, HRTEM, XPS, H2‐TPR, CO‐TPD, NH3‐TPD, Py‐IR spectra, etc.) were performed over relevant catalysts to study the catalytic mechanism. The results suggest that prior calcination offers a better chance for the proximity between Ru and Mo precursors to produce the bimetallic catalytic structure Ru–MoOx, which produces high HDO performance. Sweet catalysis: Ru–MoOx/C catalysts from different impregnation processes were carefully studied and extensively employed for sorbitol conversion to C5/C6 alkanes in trickle‐bed reactor. The results suggest that prior calcination offers a better chance for the proximity between Ru and Mo precursors to produce the bimetallic catalytic structure Ru–MoOx, which produces high HDO performance towards biofuels synthesis. [ABSTRACT FROM AUTHOR]

Recently, we demonstrated the catalytic conversion of biomass hydrolysate and real biomass into renewable alkanes over a Ru/C catalyst with aqueous phosphoric acid (Ru/C+H3PO4) and we obtained a high yield of C5/C6 alkanes. In this study, the mechanism of sorbitol hydrodeoxygenation (HDO) into alkanes over the Ru/C+H3PO4 catalytic system was investigated by using a trickle-bed reactor. A high HDO performance was detected with a large amount of long-chain alkanes in the products. Subsequently, pre- and postcharacterization studies (N2 adsorption, XRD, X-ray photoelectron spectroscopy, TEM, NH3 temperature-programmed desorption, H2 temperature-programmed reduction, FTIR spectroscopy) were performed on the relevant catalysts to study the change of the catalytic active sites. Moreover, mineral acid experiments were performed to study the influence of phosphoric acid on the HDO performance. [ABSTRACT FROM AUTHOR]

BACKGROUND: The catalytic degradation of aqueous Fischer-Tropsch (FT) effluents to fuel gas over Ru/AC has been investigated. In order to understand the catalytic performance and stability of oxide-supported Ru catalysts, several oxide supports (titania, zirconia, γ-alumina and silica) were selected for study, with a focus on the hydrothermal stability of catalysts. RESULTS: The catalytic efficiency for transforming the oxygenates in aqueous FT effluents to C1-C6 alkanes decreased in the order: Ru/ZrO2∼ Ru/TiO2 > Ru/SiO2 > Ru/Al2O3. The conversion of alcohols was greatly suppressed over Ru/γ-Al2O3. The former two catalysts (Ru/ZrO2 and Ru/TiO2) exhibited enhanced efficiency and long-term stability (400 h) relative to Ru/SiO2 and Ru/Al2O3. N2-physisorption, XRD and SEM showed that titania and zirconia exhibited high structural stability in an aqueous environment. However, the structures of γ-alumina and silica were unstable due to significant drop in surface area and adverse changes in surface morphology. Especially for the case of the Ru/γ-Al2O3 catalyst, the γ-alumina was transformed into boehmite structure after reaction, and metal leaching and carbon deposition were extensive. CONCLUSION: Ru/ZrO2 or Ru/TiO2 may be a promising alternative for degrading aqueous FT effluents due to their long-term stability. Copyright © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The Cover shows the catalytic conversion of biomass hydrolysate into renewable alkanes over a Ru/C catalyst with aqueous phosphoric acid (Ru/C+H3PO4), in which a high yield of C5/C6 alkanes was obtained.In their Full Paper, Y. Weng et al. investigated the mechanism of the sorbitol hydrodeoxygenation (HDO) reaction into alkanes over a Ru/C+H3PO4 catalyst by using a trickle‐bed reactor. Higher HDO performance might be a result of the bifunctional role of the catalytic system. These findings suggest that the downstream process of biomass hydrolysis could be directly conducted in acid aqueous phase at low reaction temperature, reducing the amount of acid waste. [ABSTRACT FROM AUTHOR]