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MnO2 based electrochemical enzyme-free glucose sensors remain significantly limited by their low electronic conductivity and associated complex preparation. In this paper, an MnO2 nanosheet array supported on nickel foam (MnO2 NS/NF) was prepared using a simple hydrothermal synthesis and employed as a 3D integrated electrode for enzyme-free glucose detection. It was found that MnO2 NS/NF shows high performance with a wide linear range from 1 μM to 1.13 mM, a high sensitivity of 6.45 mA mM-1 cm-2, and a low detection limit of 0.5 μM (S/N = 3). Besides, MnO2 NS/NF shows high selectivity against common interferences and good reliability for glucose detection in human serum. This work demonstrates the promising role of MnO2 NS/NF as an efficient integrated electrode in enzyme-free glucose detection with high performance.

Cobalt phosphate (CoPO) is gaining increasing interest as an alternative to noble metals in electrocatalytic applications. Here, we report the controlled synthesis of flower-like CoPO microsheet arrays supported on Ni foam (CoPO MA/NF) via a simple hydrothermal reaction, and their direct use as a 3D integrated anode for non-enzymatic glucose sensing. The catalytic activity of CoPO MA/NF towards glucose oxidation was evaluated by electrochemical tests. Results show that CoPO MA/NF displays high performance for glucose sensing with a short response time of less than 10 s, a low detection limit of 1 μM (S/N = 3), and a high sensitivity of 3.55 mA mM−1 cm−2. In addition, CoPO MA/NF shows excellent selectivity in the presence of interfering agents such as dopamine, uric acid and ascorbic acid, which makes it reliable for glucose detection in real human serum samples. This work not only provides the controlled synthesis of a CoPO 3D integrated electrode by a simple process, but also explores the potential application of the CoPO-based electrode material for electrochemical sensing of biochemical analytes.

We embedded Ru nanoparticles into mesoporous TiO2 submicrospheres (MTSSs) with tunable morphologies for benzene selective hydrogenation (BSH). It was identified that the TiO2 precursor prepared by ...

Defects engineering as an effective strategy was widely utilized to modulate catalytic performance for heterogeneous catalysts through tuning surface electronic surface and creating more active sites. In this work, porous Co-Mn oxide nanosheets with abundant oxygen vacancies (OVs-CMO NSs) were prepared via a simple "one-stone-two-birds" method. OVs were verified by various characterizations and found more favorable for O

Engineering the crystal facets and the proportion of edge and corner atoms of brookite TiO2 to expose more coordinatively unsaturated (cus) atoms and open-coordinated sites is of significant importance in boosting the loaded metal nanoparticle (NP) efficiency in heterogeneous catalysis, but suffering tremendous challenge owing to the low structural symmetry and thermodynamic metastability of brookite TiO2. Herein, we prepared brookite TiO2 with nanoflower (NF), nanorod (NR), and nanosheet (NS) shapes, which increased in the catalytically active cus Ti atoms on high-energy facets and the open-coordinated sites on edge and corner atoms. These increments were found to boost the loaded Ru NPs efficiency in selective hydrogenation of benzene to cyclohexene both in activity and selectivity. Combined with comprehensive characterizations, the increased turnover frequency of benzene was ascribed to the increment in the amount and strength of benzene adsorbed on the above catalytically active sites of brookite TiO2, which reacted with spillover hydrogen (Hso) dissociated from Ru NPs. For the improvement in cyclohexene selectivity, it was speculated to be originated from the elevation of the hydrogenation rate constant ratios of benzene to cyclohexene and cyclohexene to cyclohexane steps and the acceleration of cyclohexene desorption once it is formed on the catalyst by the cus Ti atoms and the open-coordinated sites on brookite TiO2.

It is very attractive to construct 3D integrated enzyme-free electrodes for sensitive and selective glucose sensing. In this paper, a novel 3D integrated electrode based on amorphous Ni-B nanoparticle grown on Ni foams (Ni-B/NF) was presented and used for enzyme-free glucose detection. Ni-B/NF was prepared via a simply and rapid electroless deposition with dipping Ni foams into NiCl2 precursors and NaBH4 reducing solutions alternatively. Electrochemical measurements demonstrate that Ni-B/NF has excellent catalytic activity for glucose oxidation and can be used as an efficient enzyme-free electrochemical sensor, with a short response time less than 10 s, a wide detection range from 5 μM to 2.66 mM, a response sensitivity of 8.25 mA mM −1 cm −2, and a low detection limit of 5 μM (S/N = 3). Moreover, the selectivity and reliability for practical application in blood glucose detection of the as-fabricated sensor were also investigated in detail.

Using P25 TiO2 as the precursor, phase-pure anatase and rutile TiO2 as well as TiO2 with tunable anatase-to-rutile molar ratios (nA/nR) were prepared via a facile “selective chemical dissolution” approach. The Ru/TiO2 catalysts were then synthesized and comprehensively characterized by spectroscopic techniques and transmission electron microscopy. It is confirmed that these catalysts possessed similar physicochemical parameters and hydrophilicity, but different Ru sizes (2.3–4.5 nm). Ru nanoparticles (NPs) supported on TiO2 with nA/nR of 2.66 (Ru/TiO2-1.5%HF) exhibited moderate size of 3.4 nm and electron-deficient state, which was originated from the unique Ru-on-anatase/rutile junction structure. In selective benzene hydrogenation, the turnover frequencies of benzene of the mixed phase TiO2-supported Ru catalysts were similar irrespective of the nA/nR ratios and ranged between phase-pure anatase and rutile TiO2-supported Ru catalysts, which can be ascribed to the size effect of Ru. For the cyclohexene selectivity, Ru NPs supported on TiO2 with nA/nR of 0.88–2.66 exhibited higher S0 (92–95%) than Ru NPs on TiO2 with other nA/nR ratios, in which the Ru/TiO2-1.5%HF catalyst displayed a maximum of 95%. We demonstrated that in addition to the proper Ru size, the electron-deficiency of Ru on the Ru/TiO2-1.5%HF catalyst contributed greatly to the highest selectivity since it can promote the desorption of cyclohexene to avoid suffering over-hydrogenation.

Support facet effect of supported metal catalysts for conversion of environmentally toxic feedstock to value-added product is challenging but of significant importance for the understanding of the reaction mechanism and accordingly rational design of newly high-efficient catalytic materials. We report here the effect of the exposed degree of TiO2 {1 0 0} facets, which was facilely tuned by hydrothermal temperature, on benzene selective hydrogenation to cyclohexene over TiO2-supported nanoparticulate Ru catalysts. It is found that the Ru/TiO2 catalyst exposed the most {1 0 0} facets exhibited slightly lower intrinsic activity, but unexpectedly highest selectivity towards cyclohexene (initial selectivity of 93%). A positively linear correlation between the initial selectivity to cyclohexene and the amount of surface OH groups on the Ru/TiO2 catalysts, which was determined by the exposed degree of TiO2 {1 0 0} facets, was identified. This linearity rationalizes the selectivity enhancement of the Ru/TiO2 catalyst exposed more {1 0 0} facets since the surface OH groups functioned in increasing the hydrophilicity of the catalysts, decreasing the type of adsorption sites of cyclohexene, and blocking the chemisorption sites of cyclohexene.

Here, we report the controllable synthesis of porous MnxCo1−xO microspheres and tunable catalytic activity in the oxidase mimicking reaction. Mn0.6Co0.4O possesses the best oxidase mimicking activity and can be used successfully in sulfide ion colorimetric detection with a low detection limit of 0.1 μM.

Here, we report highly dispersed small ruthenium nanoparticles (NPs) anchored onto a porous carbon (Ru/PC) with a clean catalytic surface and explore their excellent peroxidase-like activity for 3,3′,5,5′-tetramethylbenzidine oxidation mediated by H2O2, which allows sensitive colorimetric detection of H2O2 with a low detection limit of 3.8 μM. Moreover, it is also found that the Ru/PC has a high nitroreductase-like activity for 4-nitroaniline reduction triggered by NaBH4.

High electrical conductivity and more active sites exposure are crucial for improving the performance of electrocatalyst. Binary metal oxide nanoarray grown on conductive substrate offers a 3D self-supported electrode with a great promise in boosting its performance in enzyme-free glucose sensing. Here, NiMoO4 nanosheet arrays anchored on carbon cloth (NiMoO4 NSA/CC) was prepared via a simple hydrothermal synthesis and used as 3D self-supported electrode for enzyme-free glucose sensing. The morphology and composition of NiMoO4 nanosheet have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The electrochemical results show that NiMoO4 NSA/CC exhibits remarkable high catalytic activity towards glucose oxidation, with a wide linear response ranging from 1 μM to 0.9 mM, a high sensitivity of 4.13 mA/mM·cm2, and a low detection limit of 1 μM (S/N = 3). The enhanced performance might be attributed to the merits of nanosheet arrays with large surface area, self-supported electrode with 3D open network, as well as bimetallic component with high conductivity. Furthermore, NiMoO4 NSA/CC also shows good selectivity and reliability for glucose detection in human serum. This work offers a new pathway for the construction of enzyme-free glucose sensor with high performance.

On basis of the galvanic replacement between the previously supported Fe, Ni, Cu, and Co nanoparticles (NPs) and Ru salt followed by acid treatment, a novel strategy was developed for the fabrication of bimetallic Ru–M/TiO2 (M = Fe, Ni, Cu, Co) nanocomposite catalysts. The surface structure, composition, chemical state, and acidic properties of the catalysts were comprehensively investigated by transmission electron microscopy, X-ray photoelectron spectroscopic spectrum, and Fourier transformed infrared spectroscopy of adsorbed pyridine. It is identified that the Ru species on the Ru–M/TiO2 catalysts were electron-deficient owing to the electron-donation from Ru to sacrificial templates. In benzene selective hydrogenation to cyclohexene, the turnover frequencies of benzene on the Ru–Fe/TiO2, Ru–Ni/TiO2, and Ru–Co/TiO2 catalysts are similar and higher than that on the Ru–Cu/TiO2 catalyst, whereas the selectivity to cyclohexene increased in the order of Ru–Fe/TiO2

High electrical conductivity and the exposure to more active sites are crucial to boost the performance of a glucose sensor. A porous binary metal oxide nanoarray integrated on a binder-free 3D electrode is expected to offer a highly sensitive sensing platform. As a model, porous NiCo2O4 nanowire arrays supported on carbon cloth (NiCo2O4 NWA/CC) have been prepared and used for enzyme-free glucose sensing. NiCo2O4 NWA/CC shows larger effective surface area, superior electronic conductivity, and higher catalytic activity towards enzyme-free glucose sensing, with a linear range from 1 μM to 0.63 mM, a sensitivity of 4.12 mA mM−1 cm−2, and low detection limit of 0.5 μM. Moreover, NiCo2O4 NWA/CC also displays good selectivity and stability and thus, it can be reliable for glucose detection in human serum samples. These findings inspire the fabrication of a high-performance electrochemical sensing platform by preparing porous binary metal oxide nanoarrays supported on a 3D conductive substrate.

Benzene selective hydrogenation to cyclohexene, which has been attracting attention in terms of atomic economy, feedstock accessibility, and operational facilitation, has been investigated on Ru catalysts supported on AlOOH–SiO2 composites with varying Al/Si ratios aiming at unveiling the effect of support acidity. Various techniques such as Fourier transform infrared spectroscopy of adsorbed pyridine, transmission electron microscopy, and extended X-ray absorption fine structure spectroscopy were employed to comprehensively characterize the catalysts. It is confirmed that the amount of Lewis acid sites increased steadily with the increase in the Al/Si molar ratio. In benzene selective hydrogenation, the turnover frequency of benzene linearly correlated with the amount of acid sites, while the cyclohexene selectivity showed a volcano-type trend, achieving a maximum of 81%. Kinetic investigation revealed that the Lewis acid sites promoted the rate constants of both the benzene hydrogenation and cyclohexene hydrogenation steps to inequable extents. The resulting ratios of the rate constants evolved parallel to the variation in the cyclohexene selectivity, which elucidated the volcano-type relationship between the cyclohexene selectivity and the amount of Lewis acid sites.

Hierarchical Co(OH)2 nanotube arrays grown on carbon cloth (Co(OH)2 NTAs/CC) were prepared by a simple two-step approach. Firstly, the layered cobalt carbonate hydroxide nanowire arrays grown on carbon cloth (LCCH NWAs/CC) were prepared by chemical bath deposition. Then, the obtained LCCH NWAs/CC was converted to Co(OH)2 nanotube arrays supported on CC (Co(OH)2 NTAs/CC) through an anion-exchange reaction. Benefiting from the hierarchical structure of nanotube arrays and 3D self-supported construction, Co(OH)2 NTAs/CC shows high performance for non-enzymatic glucose sensing with a wide linear range from 1 μM to 0.6 mM, a remarkable sensitivity of 2.77 mA mM−1 cm−2, a low detection limit of 0.5 μM (S/N = 3), a good selectivity against common interferents, and a reliability for glucose detection in human serum samples.

CuCo2O4 nanowire arrays supported on carbon cloth (CuCo2O4 NWAs/CC) were prepared via a simple hydrothermal synthesis and subsequent calcination process. As a 3D binder-free electrode for non-enzymatic glucose sensing, CuCo2O4 NWAs/CC shows high sensing performance towards glucose under alkaline conditions, with a wide detection range from 1 μM to 0.93 mM, a low detection limit of 0.5 μM (S/N = 3), and a high detection sensitivity of 3.93 mA mM−1 cm−2. Moreover, CuCo2O4 NWAs/CC shows good selectivity in the presence of common interferents and good reproducibility for glucose detection, which make it a promising electrode material for sensitive determination of glucose in human samples.

Activated carbon supported Pt (Pt/AC) and Fe modified Pt (Pt–Fe/AC) catalysts have been investigated for selective hydrogenation of p-chloronitrobenzene to p-chloroaniline. It was found that the incorporation of an appropriate amount of Fe (4 wt%) resulted in a remarkable increase in activity and selectivity to p-chloroaniline, and the catalytic hydrodechlorination over the catalyst was fully suppressed at complete conversion of p-chloronitrobenzene. X-ray photoelectron spectroscopy (XPS) revealed the electron transfer from Pt nanoparticles to Fe2O3, leading to the electron-deficient state of the Pt nanoparticles in the present catalyst, which is responsible for improved performance of the Pt–Fe/AC catalyst for p-chloronitrobenzene hydrogenation to p-chloroaniline.

Ultrafine and monodispersed iridium nanoparticles supported on nitrogen-functionalized carbon materials (Ir/NC) were prepared and served as an efficient oxidase mimic for 3',5,5'-tetramethylbenzidine (TMB) oxidation. Due to the inhibition effect of glutathione (GSH) on TMB oxidation, a sensitive colorimetric GSH detection approach was proposed.

Commercially available copper foam (CF) was used as a 3D porous electrochemical sensing platform for nonenzymatic glucose detection. CF shows high electrocatalytic activity towards glucose oxidation and can be used directly for glucose electrochemical sensing without any pretreatment. The sensor exhibits high performance towards glucose in 0.1 M NaOH solution with the linear range from 1 μM to 0.5 mM, the sensitivity of 5.85 mA mM−1 cm−2 and the detection limit of 0.5 μM (S/N=3) simultaneously. Furthermore, the sensor shows a high selectivity for glucose against the common interferences and good reliability for glucose detection in human serum samples.

Pt nanoparticles with size between 2 and 7 nm supported on TiO2 were prepared by a deposition–precipitation method. These catalysts were characterized by nitrogen sorption, powder X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The effects of Pt loading and reaction conditions on the hydrogenation properties of 3-nitroacetophenone over Pt/TiO2 were investigated. The results show that the catalytic performance of Pt/TiO2 for 3-nitroacetophenone hydrogenation to 3-aminoacetophenone is better than those of Rh/TiO2 and Rh/SiO2. The specific activity of Pt in the Pt/TiO2 for 3-nitroacetophenone hydrogenation increases nearly two times when the Pt loading in the Pt/TiO2 decreases from 1.5 wt% to 0.3 wt%. The selectivity to 3-aminoacetophenone can be up to 100% at complete conversion of 3-nitroacetophenone over the 0.3 wt% Pt/TiO2 even at high temperature and H2 pressure. The high activity and excellent selectivity of the 0.3 wt% Pt/TiO2 are primarily derived from Pt nanoparticles and TiO2 support as well as the interaction between them. The reaction conditions also have a pronounced effect on the catalytic performance. Higher reaction temperature, H2 pressure and polar solvent are favorable for 3-nitroacetophenone hydrogenation to 3-aminoacetophenone over the 0.3 wt% Pt/TiO2.

Hierarchical Cu/Cu(OH)2 nanorod arrays grown on commercially available Cu foam (Cu/Cu(OH)2 NRA/CF) was prepared via a three-step strategy involving the wet chemical synthesis of Cu(OH)2 NRA/CF, a chemical reduction reaction for conversion from Cu(OH)2 NRA/CF to Cu NRA/CF, and finally galvanostatic anodization to grow Cu(OH)2 nanoparticles on Cu NRA/CF. Hierarchical Cu/Cu(OH)2 NRA/CF shows high catalytic activity towards glucose oxidation in an alkaline solution and can serve as a promising electrode material for enzyme-free glucose sensing. At an applied potential of +0.5 V, the sensor showed a broad detection range of 0.001–1.0 mM, a high sensitivity of 9.18 mA mM−1 cm−2, and a low detection limit of 0.45 μM (S/N = 3). Furthermore, the sensor exhibits excellent selectivity against common interferents and good reliability for glucose detection in human serum samples.

Nanoporous Co3O4 nanowires (NCoNWs) were synthesized via a two-step process with hydrothermal growth of cobalt nanowires (NWs) precursors and subsequent calcination of corresponding precursors in air. The structures and morphologies of the resulting cobalt NWs precursors and NCoNWs were characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM) and transmission electron microscopic (TEM). NCoNWs show high electrocatalytic activity toward glucose oxidation in alkaline medium and be used for non-enzymatic electrochemical detection of glucose. The sensor displays a high sensitivity of 300.8 μA mM−1 cm−2, a low detection limit of 5 μM (S/N = 3), and a wide linear dynamic range (5.0 × 10−6–5.7 × 10−4 M). Furthermore, the sensor exhibits a high selectivity for glucose against the common interferences including ascorbic acid, uric acid and dopamine which co-exist with glucose in human serum samples.

Ever-growing efforts have been devoted to developing cost-effective and earth-abundant electrocatalyst with high-performance in biosensing and energy energy conversion. In this work, amorphous Ni-P nanoparticles anchoring on Ni foam (Ni-P/NF) was prepared through a facile electroless deposition approach. The morphology and composition were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). As an integrated electrode, Ni-P/NF exhibits excellent catalytic activity towards glucose oxidation, with a high sensitivity of 13.89 mA mM-1 cm-2, a low detection limit (LOD) of 1 µM, a wide detection ranges from 2 µM to 0.54 mM, and a quick response (< 10 s). The selectivity and reliability for practical application in blood glucose detection were also investigated in detail. In addition to electrocatalytic glucose oxidation, Ni-P/NF shows remarkable catalytic activity towards oxygen evolution reaction (OER) in alkaline solution, and it only needs an overpotential of 360 mV to afford 50 mA cm-2. Moreover, Ni-P/NF shows excellent durability under alkaline OER condition. All these results demonstrate Ni-P/NF as highly efficient integrated anode in both biosensing and energy conversion.

Direct growth of binary metal oxide nanoarray catalyst on 3D conductive substrate offers electrode materials with high conductivity and large specific surface area, representing an effective strategy to boost the performance of electrocatalyst. In the paper, we report the construction of ZnCo2O4 nanowire arrays supported on carbon cloth (ZnCo2O4 NWAs/CC) and its application for enzyme-free glucose oxidation. ZnCo2O4 NWAs/CC was prepared via a simple hydrothermal synthesis with subsequent calcination process. As an 3D self-supported enzyme-free electrode for glucose sensing, ZnCo2O4 NWAs/CC exhibited excellent catalytic activity with a high sensitivity of 3.88 ​mA ​mM-1 ​cm-2, a wide linear range from 5 ​μM to 0.5 ​mM, and a low detection limit of 2.5 ​μM ​(S/N ​= ​3). Moreover, the proposed sensor shows high selectivity and good reliability for real sample analysis.

High electrical conductivity and more active sites exposure are crucial for improving the performance of electrocatalyst. Binary metal oxide nanoarray grown on conductive substrate offers a 3D self-supported electrode with a great promise in boosting its performance in enzyme-free glucose sensing. Here, NiMoO

Anatase TiO 2 crystallites have been prepared by hydrothermal homogeneous precipitation from Ti(SO 4 ) 2 aqueous solution with urea without using any additives. The structural evolution with the calcination temperature of the photocatalyst was studied. The photocatalytic activity of the obtained photocatalysts was investigated using X-3B dye as a model pollutant. The as-prepared anatase TiO 2 crystallites were highly resistant to thermal sintering, and the calcinations up to 800 °C were shown to enhance the crystallinity of the anatase phase without any rutile phase, which is attributed to the protection of traces of sulfate ions that are produced during the precipitation of titanium sulfate. The gradually increased photocatalytic activity of the anatase TiO 2 calcined from 110 to 800 °C demonstrated strong dependency on its crystallinity. The anatase TiO 2 calcined at 800 °C afforded the highest photocatalytic activity, which was obviously higher than that of commercial Degussa P25 on the photodegradation of X-3B dye in water under ultraviolet light irradiation, and exhibits much faster sedimentability.

One-dimensional (1D) nanobelts of several hundred micrometers in length, several hundred nanometers in width and several hundred nanometers in height are obtained by direct mixing of ortho-phenylenediamine (oPD) and FeCl3 aqueous solution at room temperature. The nanobelts were characterized by elemental analysis, liquid chromatography/mass spectrometry (LC/MS), NMR (1H and 13C), FT-IR, UV–vis, thermogravimetric (TG) and conductivity measurement. The nanobelts are identified as 2,3-diaminophenazine assemblies. The formation of the nanobelts involves two stages: (1) oxidation of oPD by FeCl3, yielding individual 2,3-diaminophenazine molecules; and (2) self-assembly of the 2,3-diaminophenazine, forming the 1D nanobelts. The nanobelts exhibit fairly high thermal stability and show conductivity at the level of semiconductors.

A highly active and selective K-Pd/MnOx-ZrO2-ZnO catalyst for the one-step synthesis of 2-pentanone from ethanol is described. The possible reaction pathways for ethanol reaction over K-Pd/MnOx-ZrO2-ZnO catalyst were investigated by means of TPSR, CO2- and NH3-TPD techniques. The reactions were performed in a fixed bed continuous flow reactor. Complete conversion with high selectivity for 2-pentanone, was observed under 370 similar to 390degreesC, 2 similar to 4 MPa, GHSV = 8000 similar to 10,000 h(-1) and LHSV < 1.25 h(-1) conditions. Ethanol reactions over K-Pd/MnOx-ZrO2-ZnO catalyst showed that the catalyst could catalyze dehydrogenation. aldol. dehydration and hydrogenation reactions. Both acidic and basic properties are found on the surface of K-Pd/MnOx-ZrO2-ZnO catalyst, whose multifunctionality with the combination of basic, acid and metal sites may be responsible for the efficiency of the K-PdMnOx-ZrO2-ZnO catalyst. (C) 2004 Elsevier B.V. All rights reserved.

The catalytic performances of ZrO2-based catalysts were evaluated for the synthesis of higher alcohols from synthesis gas. The crystal phase structures were characterized by X-ray diffraction (XRD) and UV Raman. The results indicated that ZrO2 and Pd modified ZrO2 catalysts were effective catalysts in the synthesis of ethanol or isobutanol, and their selectivities basically depended on the crystal phase of ZrO2 surface. The ZrO2 with surface tetragonal crystal phase exhibited a high activity to form ethanol, while the ZrO2 with surface monoclinic crystal phase exhibited a high activity to form isobutanol. Temperature-programmed desorption (TPD) experiment indicated that the high activity of isobutanol formation from synthesis gas over monoclinic zirconia was due probably to the strong Lewis acidity of Zr4+ cations and the strong Lewis basicity of O2− anions of coordinative unsaturated Zr4+–O2− pairs on the surface of monoclinic ZrO2.

ZrO2-A and ZrO2-B catalysts were prepared by two different coprecipitation methods and their performance of CO hydrogenation was studied. The results indicated that ZrO2 and Li-, Pd- and Mn-modified ZrO2 catalysts exhibited good selectivity and high STY to higher alcohols. The surface characteristics of ZrO2-A and ZrO2-B samples were investigated by means of BET, NH3-TPD, XRD and UV Raman technique. The tetragonal zirconia on the surface region of ZrO2-A and Li-Pd-Mn/ZrO2-A catalysts may be responsible for the high selectivity towards ethanol, while the monoclinic zirconia on the surface of ZrO2-B and Li-Pd-Mn/ZrO2-B catalysts may be crucial to the high isobutanol selectivity.

MnO 2 -doped anatase TiO 2 was prepared by precipitation–hydrothermal crystallization method. The as-prepared MnO 2 -doped anatase TiO 2 has a good thermal stability even after calcination up to temperature as high as 800 °C. With increasing calcination temperature, the photocatalytic activity of the MnO 2 -doped anatase TiO 2 increased gradually. The sample calcined at 800 °C afforded the dramatic photocatalytic activity, which was comparable to that of the Degussa P25 TiO 2 . Compared with the P25 TiO 2 , the particle size of the MnO 2 -doped anatase TiO 2 calcined at 800 °C is big, which is very easy to separate from reaction mixture.

The effect of calcination temperature on the textual structure and catalytic properties of amorphous MnOx for the liquid-phase aerobic oxidation of benzyl alcohol was studied. The amorphous nature of the synthesized MnOx was retained when the calcination temperature was lower than 400°C, and calcination temperatures higher than 500°C led to the transformation of amorphous MnOx to crystalline OMS-2 and Mn 2 O 3 . Catalytic reaction studies revealed that the amorphous MnOx exhibited higher mass specific activity than OMS-2, Mn 2 O 3 , and γ-MnO 2 , and MnO x calcined at 110°C showed the highest activity. An inverse linear correlation between the onset reduction temperature in H 2 -TPR and the mass specific activity of the various manganese oxides was observed. These results suggest that the reducibility of manganese oxide is the key factor responsible for its activity for the aerobic oxidation of benzyl alcohol.

Anatase TiO2 nanocrystallites were prepared from TiCl4 with addition of aqueous ammonia by changing Ti(OH)4 hydrogel into its corresponding alcogel followed by supercritical drying in ethanol medium. The as-prepared TiO2 was characterized by XRD, TG and BET. The results show that the prepared anatase TiO2 has remarkable high thermal stability. The anatase structure of the prepared TiO2 is maintained even after calcination up to temperatures as high as 800 °C. The photocatalytic activity of the prepared TiO2 calcined at 800 °C in degradation of reactive brilliant red X-3B is comparable to commercially available nanosized P25 TiO2.

Selective production of chloroanilines from chloronitrobenzenes without any dechlorination was found feasible by catalytic hydrogenation over zirconia-supported gold catalyst, which uncovers a clean synthetic approach for useful chloroanilines.