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• A Co-Mn bimetallic catalyst supported on MCM-41 was synthesized. • This catalyst is capable of performing photothermal CO 2 oxidative dehydrogenation of propane. • The activity is partially derived from enhanced electron transfer and photothermal conversion. • The remarkable photoelectric properties also significantly contribute to the catalytic reaction. Compared with conventional thermal catalysis reaction, the photothermal CO 2 -assisted oxidative dehydrogenation of propane (CO 2 -ODHP) to produce propylene and CO is an environmentally friendly and sustainable method that operates at lower temperatures. In the present work, we have developed a series of Co-Mn/MCM-41 catalysts and utilized them in the photothermal CO 2 -ODHP reaction. Among these catalysts, the sample with Co and Mn loadings of 3 % resulted in activities of 225.7 μmol g cat −1 h−1 of propylene and 272.0 μmol g cat −1 h−1 of CO at 250 °C. Characterization results revealed that the electron transfer and interplay between Co and Mn oxides enhance the photoelectronic response and reduce impedance, facilitating the electron transfer process. Besides, the Co and Mn bimetallic species could enhance photothermal conversion efficiency and further enhance the local temperature during the reaction. The present work introduces a novel strategy for building supported bimetallic oxides in achieving CO 2 -ODHP via the photothermal route and is also expected to provide an optional catalyst required satisfactions including efficient electron transfer and photothermal conversion for other photothermal reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Precious metal-free Co 3 Cu 1 O x catalyst is active for the selective hydrogenation of quinolines at low temperature (60 °C). • The high activity for the Co 3 Cu 1 O x catalyst is related to the high H 2 absorption ability. • The gram-scale experiment of hydrogenation of quinoline gave 92% yield to 1,2,3,4-tetrahydroquinoline. • The easily prepared and magnetic Co 3 Cu 1 O x catalyst could be reused at least five times without obvious loss in activity. Quinoline derivatives are widely exist in the environment, and mainly separated from the coal tar pitch fraction. Hydrogenation of these compounds to 1,2,3,4-tetrahydroquinolines, an important class of natural products and medicinal agents, is a significant transformation of waste to valuable chemicals. In the present work, we developed a cheap and highly efficient Co 3 Cu 1 O x bimetallic catalyst and used it for the hydrogenation of quinolines at a temperature down to 60 °C. The introduction of Cu into Co catalyst changed the physical and chemical features of Co catalyst, which was characterized by Raman spectra, N 2 -adsorption/desorption isotherms, H 2 -TPR and H 2 -TPD tests. The recycling experiments indicated the catalyst was stable and possessed good reusability. Importantly, the gram-scale experiment provided a high yield (92%) to the target product, demonstrating that the catalytic system has a potential practical application. [ABSTRACT FROM AUTHOR]

Photothermal oxidation of cyclohexane with molecular oxygen in solvent-free is considered to be an efficient approach for the formation of cyclohexanone and cyclohexanol (KA oil), and possesses the potential to generate the next stage product of adipic acid (AA) by one-pot oxidation in chemical industry. Herein, a unique type of Co 8 La 1 O x /WO 3 Z-scheme nanocomposites with p-n heterojunction was successfully constructed by a facile process of solvothermal reaction in conjunction with the simple impregnation method. The Co 8 La 1 O x /WO 3 Z-scheme heterojunction nanocomposites achieved an excellent catalytic performance for the photothermal oxidation of cyclohexane at 120 ℃ under visible light in solvent-free conditions. Surprisingly, 10.35% conversion of cyclohexane with 98.75% selectivity of KA oil (liquid, 80.97%) and AA (solid, 17.78%) was achieved during the reaction time of 3 h. Moreover, the desirable durability and stability of the Co 8 La 1 O x /WO 3 composites demonstrated a potential application as an industrial catalyst. The outstanding catalytic performance of the Co 8 La 1 O x /WO 3 composites could be ascribed to the enhanced electron excitation capacity, the accelerated electron-hole separation and migration, the inhibited charge recombination, the strong visible-light absorption, and the efficient synergetic catalytic effect of photo-thermo. Besides, high oxygen adsorption capacity and large specific surface area of the Co 8 La 1 O x /WO 3 composites can efficiently build a bridge between cyclohexane and O 2 to fully utilize the oxygen participation in the oxidation. The present approach provides a promising perspective for the designing and constructing of Z-scheme heterojunction catalyst with a high-efficiency photo-thermo catalytic performance in the oxidation of cyclohexane to KA oil and AA in chemical industry. [Display omitted] • Co 8 La 1 O x /WO 3 Z-scheme nanocomposites with p-n heterojunction were successfully constructed. • The Co 8 La 1 O x /WO 3 can achieve highly efficient and selective photothermo catalytic oxidation of cyclohexane in solvent-free. • 10.35% conversion of cyclohexane with 98.75% selectivity to KA oil (liquid, 80.97%) and AA (soild, 17.78%) was achieved for 3 h. • Possible mechanism for enhancing photo-thermo catalytic performance was proposed. [ABSTRACT FROM AUTHOR]

• A series of CeCuCoO x /MCM-41 catalysts were successfully synthesized by the equivalent-volumetic impregnation method. • The Ce 4 Cu 6 Co 0.5 O x /MCM-41 with strong acidic sites exhibited an excellent catalytic performance for the nitration of acetanilide with equivalent dilute nitric acid. • The acetanilide conversion of 91% with 91.6% selectivity to mono-nitroacetanilide was achieved over the Ce 4 Cu 6 Co 0.5 O x /MCM-41 catalyst. • Possible catalytic mechanism of electrophilic substitution by solid acidic catalyst was proposed. The development of solid acidic catalyst is of great significance to the safe, controllable, efficient and environment-friendly nitration of aromatics. Herein, a series of trimetallic supported catalysts were obtained by the equivalent-volumetic impregnation method. In the as-prepared Ce 4 Cu 6 Co 0.5 O x /MCM-41 catalyst with strong acidic sites, the metal oxide particles mainly distributed in a form of nanowires in MCM-41 molecular sieve channels. And, the Ce 4 Cu 6 Co 0.5 O x /MCM-41 catalyst exhibited an excellent catalytic performance for the nitration of acetanilide with equivalent dilute nitric acid as a nitration reagent. Surprisingly, 91% conversion of acetanilide with 91.6% selectivity to mono-nitroacetanilide was achieved. The nitration of acetanilide obviously exhibited a typical ortho-para nitration effect of the aromatics. Furthermore, an excellent stability and acceptable reusability proved a potential to replace the nitration system of concentrated acid in chemical industry. The Lewis acid sites of Ce 4 Cu 6 Co 0.5 O x /MCM-41 solid acid catalyst can act a similar role to a strong protic acid in mixed acid system, which can polarize nitric acid molecules to form active NO 2 + reagents. Meanwhile, the abundant strong acidic sites of solid acidic Ce 4 Cu 6 Co 0.5 O x in MCM-41 channels are significantly conducive to the sorption and activation of the reactants. The present work provides a prospective strategy for constructing a solidic acid catalyst with an eco-friendly nitration of aromatics. [Display omitted] [ABSTRACT FROM AUTHOR]

• A series of FeNiCu/MCM-41 catalysts were successfully synthesized by the impregnation method. • A desired efficient and selective hydrogenation of quinolines was achieved at low temperature and in solvent-free system. • 58% Fe 4 Ni 6 Cu 5 /MCM-41 catalyst achieved 97.5% conversion and exceeding 98% selectivity to tetrahydroquinoline under mild conditions. • Possible catalytic mechanism of the synergism of Fe-Ni and Ni-Cu alloys was proposed. The development of non-precious metal catalysts in heterogeneous catalytic processes is of great importance to the hydrogenation of quinolines for both theoretical and industrial applications. Herein, an effective non-precious metal catalyst, 58% Fe 4 Ni 6 Cu 5 /MCM-41, was developed to catalyze the hydrogenation of quinolines under the green and mild conditions, which can achieve 97.5% conversion and exceeding 98% selectivity to tetrahydroquinoline in solvent-free at low temperature of 50 °C. Moreover, the acceptable results of the reusability and gram scale-up experiments proved an industrial application potential of the as-prepared catalyst. Meanwhile, in cyclohexane system, 58% Fe 4 Ni 6 Cu 5 /MCM-41 catalyst can further realize a higher activity of the hydrogenation at a lower temperature of 40 °C, achieving 98.2% conversion and 98% selectivity to tetrahydroquinoline. The existence of Fe-Ni and Ni-Cu alloys in Fe 4 Ni 6 Cu 5 /MCM-41 catalyst was demonstrated by TEM, XRD, XPS, H 2 -TPD, and Raman spectroscopy. And, Fe-Ni and Ni-Cu alloys can be well dispersed onto MCM-41 molecular sieves. For Fe 4 Ni 6 Cu 5 /MCM-41 catalyst, quinoline molecules can be adsorbed by Fe3+ species on the surface of Fe-Ni alloy through the coordination, while hydrogen molecules can be adsorbed and activated by Ni-Cu alloy. Under the synergism of Fe-Ni and Ni-Cu alloys, the highly effective and selective hydrogenation of quinolines was achieved at low temperature and in solvent-free system. The present approach offers a prospective idea for building non-precious metal catalysts to realize the effective hydrogenation of N-heterocyclic compounds under mild conditions. [Display omitted] [ABSTRACT FROM AUTHOR]