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In this work, CuOx/mesoporous Hangjin 2# clay catalysts were synthesized from Cu(NO3)2 and Hangjin 2# clay in one step. The prepared catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption measurements, high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray analysis (EDX), and UV–visible diffuse reflectance spectroscopy (DRUV). These materials were employed in photocatalytic benzene hydroxylation to phenol with H2O2 as the oxidant, and the effects of the copper loading and light source on the reaction were studied. The results show that the phenol selectivity and yield initially increased and then decreased with increasing copper content. Under the optimized reaction conditions, the phenol selectivity and yield were 91.9 % and 25.6 %, respectively. Catalyst is still active after the repeat three times.

We systematically investigate the structural, electronic and magnetic properties, bonding analysis, as well as surface morphology of transition metal monoxides (FeO, CoO and NiO) utilizing density functional theory (DFT) with various functionals across from GGA to GGA+U and hybrid functional. Our results reveal that the screened hybrid functional (HSE) could give a reasonable description on structural and electronic properties of these strongly correlated systems when compared to experiments. Local approximation GGA functional fails to yield the accuracy band gaps. GGA+U approximation are rational when given a reasonable U, but the U which reproduce a reasonable band gap often yield a significant error in describing other properties such as lattice constant or magnetic moment. The computed Crystal Orbital Overlap Population (COOP) indicates that cubic FeO and CoO are metastable phase, while the distortion occurs to enhance stability. Based on the reliable functional, the surface morphology of FeO, CoO and NiO are predicted using Wulff construction approach.

Hydrotalcite-supported Pd–Au nanocatalysts were found to be efficient heterogeneous catalysts for Ullmann homocoupling reactions of aryl bromides or chlorides at 25 or 40 °C, which could be due to the ensemble effect and increased electron density of Pd sites on Pd–Au nanoparticles, and the assistant role of the hydrotalcite for the reversion of the catalytic active center, Pd(0).

Supported palladium nanoparticles are used as efficient catalysts for the synthesis of aromatic ketones via cross dehydrogenative coupling reactions of 2-arylpyridines with alkylbenzenes. The catalyst can be reused for five cycles without significantly losing activity. Mechanism research showed that alkylbenzenes were oxidized to their corresponding aldehydes and subsequently coupled with 2-arylpyridines to generate aryl ketones through a Pd0/PdII/PdIV catalytic cycle.

Catalyzed by supported palladium nanoparticles, a decarbonylative amidation reaction between various aryl esters and formamides by C–O bond activation has been developed for the synthesis of amides. The catalyst can be reused and shows high activity after five cycles. The XPS analysis of the catalyst before and after the reaction suggested that the reaction might be performed via a Pd0/PdII/PdIV catalytic cycle that began with Pd0. The hot filtration test strongly suggests that the present reaction would proceed in a heterogeneous manner.

Catalyzed by supported palladium nanoparticles, an ortho-directed C–C coupling reaction between 2-phenylpyridines and aldehydes has been developed for the selective synthesis of aromatic ketones. The catalyst is recovered and used for five times with the conversion of 2-phenylpyridine holding above 44% after recycling five times. The XPS analysis of the catalyst before and after reaction suggested that the reaction might be performed via a Pd0/PdII/PdIV catalytic cycle that began with Pd0.

Visible light can drive esterification from aldehydes and alcohols using supported gold nanoparticles (Au/Al2O3) as photocatalysts at ambient temperatures. The gold nanoparticles (AuNPs) absorb visible light due to the localized surface plasmon resonance (LSPR) effect, and the conduction electrons of the AuNPs gain the energy of the incident light. The energetic electrons, which concentrate at the NP surface, facilitate the activation of a range of aldehyde and alcohol substrates. The photocatalytic efficiencies strongly depend on the Au loading, particle sizes of the AuNPs, irradiance, and wavelength of the light irradiation. Finally, a plausible reaction mechanism was proposed, and the Au/Al2O3 catalysts can be reused several times without significantly losing activity. The knowledge acquired in this study may inspire further studies in new efficient recyclable photocatalysts and a wide range of organic synthesis driven by sunlight.

Catalyzed by supported gold nanoparticles, an aminolysis reaction between various aryl esters and inert tertiary amines by C-O and C-N bond activations has been developed for the selective synthesis of tertiary amides. Comparison studies indicated that the gold nanoparticles could perform energy-efficient green catalysis at room temperature, whereas Pd(OAc)2 could not.

Synthesis of imines from amines and aliphatic alcohols (C1–C6) in the presence of base on supported palladium nanoparticles has been achieved for the first time. The catalytic system shows high activity and selectivity in open air at room temperature.

An aminolysis reaction between various aryl esters and inert tertiary amines by C-O and C-N bond activations has been developed for the selective synthesis of a broad scope of tertiary amides under neutral and mild conditions. The mechanism may undergo the two key steps of oxidative addition of acyl C-O bond in parent ester and C-N bond cleavage of tertiary amine via an iminium-type intermediate.

Nano-gold catalysts were prepared by the liquid reduction method and employed in the oxidative esterification of alcohols under ambient conditions. The effects of the supports and gold loading on the catalytic behavior were investigated. The catalysts were characterized by transmission electron microspectroscopy, X-ray diffraction, X-ray photoelectron microspectroscopy and atomic absorption spectrometry. The results indicated that nano-scale metallic state gold was highly dispersed on the support. 95 % methyl benzoate yield was obtained over 3 wt% Au/ZrO2 catalyst at 30 °C under air atmosphere. Under optimized reaction conditions, benzyl alcohols with electron-withdrawing groups could give high selectivity to the corresponding methyl ester at moderate conversion of alcohols. However, when a benzyl alcohol with electron-donating group was used, high conversion of alcohol but low selectivity of the corresponding methyl ester was obtained. Low yields were obtained with aliphatic alcohols as substrates even at high temperature. The kinetic analysis of the oxidation from benzyl alcohol to benzaldehyde and from benzaldehyde to methyl benzoate was also described. The facile and simple procedure was a great option for direct synthesis of methyl esters from alcohols.

Mesoporous NiO was prepared by the template synthesis method, using polyethylene glycol as a template, Ni(NO3)2·6H2O and Ni(CH3COO)2·4H2O as a nickel source. The major factors that influenced the formation of mesoporous NiO, such as nickel source, calcining temperature and molecular size of PEG, were estimated. As a result, the nickel source and calcination process could determine the crystallizability and organization of mesostructured NiO particles. The molecular size of PEG surfactant is not only relevant to the pore size of mesoporous NiO, but also of effect on the selectivity to propylene. The fine mesoporous NiO could be formed by using Ni(CH3COO)2·4H2O as nickel source and PEG400 as template, and then being calcined at 400–600 °C. The mesoporous NiO catalysts exhibit significant catalytic activities for the oxidative dehydrogenation of propane. The propylene yield of 14 % was obtained at propane conversion of 27 % at 350 °C. Furthermore, the selectivity to propylene can be maintained around 50 % even at 600 °C, indicating the high catalytic stabilities of mesoporous NiO catalysts in the present work. We proposed that a non-stoichiometric oxygen species on the surface is the catalytic active site and the mesoporous structure is the key factor for the high catalytic stabilities in the light of the characteristic results of mesoporous NiO catalysts.

Imines were synthesized from benzyl alcohol and amines by using catalysts of gold nanoparticles supported on ZrO2 (Au/ZrO2). The effects of reaction time, temperature, gold loadings and base were investigated. High yields were achieved under moderate conditions (60 °C) in the presence of KOCH3. For instance, the yield of N-benzylidenebenzylamine produced from benzyl alcohol and benzylamine on 3 wt% Au/ZrO2 is 87 %. The synthesis of imine involves two reaction steps: selective oxidation of benzyl alcohol to benzaldehyde and the coupling reaction of amines with benzaldehyde. In the first step, the base promotes the selective oxidation. The reactions of benzyl alcohol with three different amines, aniline, n-butylamine and benzylamine, were conducted to produce corresponding imines. The results show that the amine with stronger nucleophilicity has better ability to react with benzaldehyde in the second step, resulting in higher yield of the corresponding imine. We proposed a tentative mechanism for the synthesis process.

SiO2 is generally regarded as an “inert” support of gold catalysts for CO oxidation. We find that silica obtained from a natural clay mineral can be used as excellent gold-support for efficient CO oxidation at relatively low temperature. Fine Au particles are found to locate around the Al sites, rather than on pure SiO2 area. Accordingly, high Au loading and catalytic activity for the clay-based SiO2 supports are ascribed to the residual aluminum originally from the clay.

Monolithic mesoporous carbons were prepared through a simple autoclaving method using citric acid as catalyst instead of HCl. The presence of citric acid plays an important role in determining the structural ordering of the resultant mesoporous structure due to the –COOH groups which can enhance hydrogen interaction between structural directing agent of triblock copolymer F127 and polymeric carbon precursor of resorcinol–formaldehyde resins. The obtained carbons have a hexagonal pore system, uniform pore size of ∼5.0 nm and high BET surface area of ∼758 m2/g. The prepared mesoporous carbons were used as catalyst for dehydrogenation of propane, exhibiting high catalytic activity and stability. After 50 h time-on-stream, the propane conversion of 12.1% was observed with propylene selectivity of 95.1% in the direct dehydrogenation process, while the propane conversion of 20.1% with propylene selectivity of 25.8% in oxidative dehydrogenation process. It has been found that the surface basic groups are active sites.

Mesoporous Ce0.8Zr0.2O2 oxides were prepared by a surfactant-assisted method of nanocrystalline particle assembly, and used as a support of nickel oxide nanocatalysts. The obtained mesoporous NiO/Ce0.8Zr0.2O2 nanocatalysts were characterized by XRD, N2 adsorption, TEM, H2-TPR and X-ray photoelectron spectroscopy techniques. The catalytic properties of the NiO/Ce0.8Zr0.2O2 nanocatalysts were evaluated by CO oxidation and toluene combustion. The results showed that the catalyst with 10 wt% NiO loading exhibited the highest catalytic activity for CO oxidation and toluene combustion.

Perovskite oxide LaCoO3 and the mixture oxides of La2O3 + Co3O4 were prepared by sol–gel method. Then Au/La–Co–O catalysts were prepared by deposition- precipitation (DP) method and characterized by means of XRD, BET, XPS, TEM and IR. The catalytic performance for CO low-temperature oxidation and stability over these catalysts were compared. The results of experiment showed gold catalysts supported on perovskite oxides have higher catalytic activity and stability than that of supported on the simple oxides.

A series of Au catalysts have been prepared at different pH using the Y-zeolites as support and the activity for CO oxidation has been tested. The results showed that the highest Au loading was obtained at pH = 6 and this catalyst demonstrated the highest activity.

A series of Co-V-O catalysts were prepared and their catalytic performances for the oxidative dehydrogenation of propane to propene were investigated. It was found that the p-type catalysts showed higher catalytic behavior than the n-type catalyst.

The example of palladium-catalyzed intermolecular cyclization for the synthesis of various diarylfurans in which one of the aromatic rings originates from the phenolic part of the starting ester and the other one from PhI(OAc)2 has been reported. The reaction is carried out through two steps: the rearrangement of palladium-associated iodonium ylides to form o-iodo diaryl ether and then palladium catalyzed intramolecular direct arylation. This reaction can tolerate a variety of functional groups and is alternative or complementary to the previous methods for the synthesis of diarylfurans.

It is demonstrated for the first time, that Al2O3-supported gold nanoparticles catalyze the aminolysis of activated aryl esters with inert tertiary amines to yield tertiary amides.

Ni–V–O series catalysts for the oxidative dehydrogenation (ODH) of propane were prepared and characterized by BET, XRD, H2-TPR, O2-TPD-MS and electrical conductivity. At 425°C a C3H6 selectivity of 49.9% was observed on Ni0.9V0.1O Y at a C3H8 conversion of 19.4%, and the obtained selectivity is almost two times higher than that over NiO at the roughly same conversion of C3H8. The mobile oxygen species created by the interaction of NiO and V2O5 has been found in the composite catalysts by O2-TPD-MS and electrical conductivity studies, which seems to be responsible for the enhanced selectivity of the propane oxidative dehydrogenation.

The oxidative dehydrogenation (ODH) of propane was investigated on Ni-V-O catalysts in a wide range of vanadium contents (5-40%). The addition of a small amount of vanadium significantly increased the catalytic activity of NiO for oxidative dehydrogenation of propane to propene. The formation of propene has a good correlation with the coexistence of NiO and Ni3V2O8. This result strongly suggests that a synergetic effect exists between them in NiXV1-XOY (X = 0.95 to 0.6). The best results were obtained with a high Ni/V ratio (e.g. X = 0.95 to 0.85). The active sites and selective oxygen species are discussed. The influence of the catalyst preparation technique and the redox properties of the catalyst were also examined.

Synthesis of imines from amines and aliphatic alcohols (C1–C6) in the presence of base on supported palladium nanoparticles has been achieved for the first time. The catalytic system shows high activity and selectivity in open air at room temperature.

An aminolysis reaction between various aryl esters and inert tertiary amines by C–O and C–N bond activations has been developed for the selective synthesis of a broad scope of tertiary amides under neutral and mild conditions. The mechanism may undergo the two key steps of oxidative addition of acyl C–O bond in parent ester and C–N bond cleavage of tertiary amine via an iminium-type intermediate.

The addition of reducible metal oxides as promoters shows a positive effect on the catalytic behavior of lanthanum vanadate (LaVO4). A C3H6 yield increase of 6.5% is observed at 500 °C on molybdenum-promoted LaVO4, which can be attributed to the change of the redox properties, the blocking of the strong oxidation sites of the catalysts and to an increase of the accessibility of the labile oxygen toward the reactant. The influence of the catalyst preparation method and of the Mo loading as well as the additional promoting effect of CO2 in the gas feed was also examined.

The catalytic performances of Mn-based catalysts have been investigated for the oxidative dehydrogenation of both ethane (ODE) and propane (ODP). The results show that a LiCl/MnOx/PC (Portland cement) catalyst has an excellent catalytic performance for oxidative dehydrogenation of both ethane and propane to ethylene and propylene, more than 60% alkanes conversion and more than 80% olefins selectivity could be achieved at 650°C. In addition, the results indicate that Mn-based catalysts belong to p-type semiconductors, the electrical conductivity of which is the main factor in influencing the olefins selectivity. Lithium, chlorine and PC in the LiCl/MnOx/PC catalyst are all necessary components to keep the excellent catalytic performance at a low temperature.

Ni3V2O8 catalyst was prepared by oxalate co-precipitation method with microwave heating in this paper. In order to study the relationship between the catalytic performance and the surface species, the catalyst was characterized by XRD, BET, H2-TPR, XPS, TEM and conductivity measurement. The surface property of Ni3V2O8 was studied by XPS and the catalytic performance of the oxidative dehydrogenation of propane to propylene was also investigated. The results of XRD showedthat pure Ni3V2O8 with nice structure was obtained. TEM experiments results demonstrated that the prepared Ni3V2O8 catalyst at 700 degrees C calcination showed uniform particle with the mean particle size of 30 nm. The surface area of the catalyst was 8.623 m2 x g(-1). The diagram of the relationship between electrical conductivity and oxygen partial pressure of Ni3V2O8 showed dsigma/dPO2,0, implying that Ni3V2O8 catalyst was a p-type semiconductor. H2-TPR results showed that only one unsymmetrical reduction peak appeared at 663.5 degreesC within 300-900 degrees C region over Ni3V2O8 catalyst and no obvious shoulder peak was observed. It could also be found that the ratio of non complete reduction oxygen species was about 33.59% (O(-) 27.55%, O2(2-) 6.04%) from the O(1s) XPS result and more V4+ species existed on the Ni3V2O8 catalyst surface. The TPR and XPS results illustrated that the transformation of the lattice oxygen to non-complete reduction oxygen in NiV2O8 catalyst might promote the oxidation-reduction reaction between different valence vanadium and promoted the oxygen vacancy formation. This then led to abundant non-complete reduction oxygen O(-) and V4+ species formation on the surface of Ni3V2O8 catalyst. The active result of oxidative dehydrogenation of propane to propylene showed that the 60.02% propylene selectivity could be reached at 18.60% propane conversion. Compared with the reported results over the coexistent NiO and Ni3V2O8 system from the literature, pure Ni3V2O8 catalyst system in this present paper showed higher propylene selectivity than the coexistent NiO and Ni3V2O8 system under the same propane conversion condition, suggesting that the performance of propane to propene is correlated to the oxidation-reduction of V4+ / V5+ couple and non complete reduction oxygen species (O(-) or O2(2-)). This result further illustrated that NiV2O8 was active phase for oxidative dehydrogenation of propane to propylene. Combining the active and characterization results, it was found that catalytic activity was correlated to the surface non-complete reduction O(-) and V4+ species, which was beneficial to improving the propylene selectivity.

The oxidative dehydrogenation of propane on rare earth vanadates is always in competition with the total oxidation of the alkane which leads to the formation of CO 2 and CO. Addition of CO 2 into the feed results in an increased C 3 H 6 selectivity together with a decreased CO formation through the total oxidation of the alkane or the formed alkene. For the tested rare earth vanadates as well as for the niobium promoted catalysts an enhancement of the C 3 H 6 selectivity at isoconversion and thus of the C 3 H 6 yields is observed upon CO 2 addition into the feed.