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[Display omitted] The highly selective oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA oil) is one of the most challenging issues in the chemical industry. However, the difficulty in attaining high selectivity and high conversion rate in parallel for the existing catalysts limits its practical application. In this paper, a novel photo-thermo synergistic catalyst was reported for the aerobic oxidation of cyclohexane. The uniform blue MoO 3-x nanowires with small diameter stabilized by polyvinyl pyrrolidone (PVP) were synthesized by a hydrothermal method, and a series of MoO 3-x -AgPd composite materials of different proportions were prepared by an in-situ reduction process. The morphology, crystalline structure, surface chemical bonding, photoelectrochemical properties of MoO 3-x -AgPd composites are thoroughly characterized. The MoO 3-x -AgPd composites present significantly increased catalytic performance than MoO 3-x nanowires in the photo-thermo synergistic catalytic oxidation of cyclohexane under dry air. The high conversion rate of 11.3% with the KA oil selectivity of 99.0% was achieved by the MoO 3-x -Ag 20 Pd 20 composites under photo-thermo catalytic process at 120 ℃, which is 1.5 times of that by MoO 3-x nanowires. Under photo-thermo catalytic process, a high cyclohexane conversion rate similar to that of higher temperature thermal catalysis can be obtained at lower reaction temperature, and more cyclohexanol can be produced with a ketone to alcohol (K/A) ratio of 0.254. The significantly enhanced catalytic activity can be attributed to the effective charge transfer in the AgPd alloy nanoparticles, the optimized band gap structure, the suppressed charge recombination, and the promoted photo-thermo synergetic catalytic effect. This work provides a new reference scheme for the design and preparation of high-efficiency photo-thermo catalysts for the selective oxidation of cyclohexane. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ozone-assisted catalysis was able to remove CO efficiently at room temperature. • Bimetallic Ag-Pd catalyst exhibited a cooperative effect. • In situ FTIR measurement provided useful insights into the mechanism of the catalytic reaction. Abstract The room-temperature oxidation of CO using ozone-assisted catalysis (OAC) over monometallic or bimetallic catalysts supported on γ-Al 2 O 3 is presented. Within the tested particle size range, ozone decomposition was insensitive to the size of the Ag particles (6.6–11.9 nm) at weight hourly space velocities of up to 360 L·g−1·h−1. Among the tested monometallic catalysts (Ag Pd, Fe, Mn, and Cu), Ag showed the highest activity for CO oxidation. Bimetallic catalysts (Ag-M or Pd-M where M = Cu, La, Ru, and Fe) were also considered by adding a second metal or perovskite oxide (LaFeO 3) to Ag. A cooperative effect was observed with the bimetallic Ag-Pd catalyst for the OAC of CO oxidation at room temperature, whereas the other bimetallic catalysts showed slightly lower performance compared to the monometallic catalyst. A high ozone utilization efficiency of 0.94 was achieved with the bimetallic Ag-Pd/γ-Al 2 O 3 catalyst. High-angle annular dark-field scanning tunneling electron microscopy (HAADF) and energy dispersive X-ray (EDX) spectroscopy measurements confirmed the proximity of the two components, which is essential for their interaction. The in situ FTIR measurements revealed that the cooperative effect in the bimetallic Ag-Pd catalyst involved modification of CO adsorption and the suppression of product accumulation. Two typical IR absorption bands of linear- (2090 cm−1) and bridge-CO (1918 cm−1) on Pd disappeared in the presence of Ag nanoparticles. Thus, the presence of Ag in contact with Pd inhibited the accumulation of carbonates, which led to enhanced catalytic performance. Adsorption site-dependent CO oxidation on Pd was also confirmed by the in situ Fourier transform IR measurement. [ABSTRACT FROM AUTHOR]

Abstract: Pd–Ag alloys containing different amounts of Ag (8, 21 and 34at.%) were prepared in order to evaluate their catalytic activity towards the ethanol oxidation (EOR) and oxygen reduction (ORR) reactions. A sequential electroless deposition of Ag and Pd on a stainless steel disc, followed by annealing at 650°C under Ar stream, was used as the alloy electrode deposition process. From half-cell measurements in a 1.0M NaOH electrolyte at ≅20°C, it was found that alloying Pd with Ag leads to an increases of the ORR and EOR kinetics, relative to Pd. Among the alloys under study, the 21at.% Ag content alloy presents the highest catalytic activity for the EOR and the lowest Ag content alloy (8at.% Ag) shows the highest ORR activity. Moreover, it was found that the selectivity of Pd–Ag alloys towards ORR is sustained when ethanol is present in the electrolyte. [Copyright &y& Elsevier]

Abstract: Porous triangular Ag–Pd nanoplates of various bimetallic ratios were prepared by a galvanic displacement reaction in which Pd(OAc)2 reacted with Ag nanoplates. In order to reduce the interaction of free hexadecyltrimethylammonium bromide (CTAB) with the synthesized Ag–Pd nanoplates during this reaction, Ag nanoplate/CTAB solution was precipitated by high-speed centrifugation before synthesizing the porous bimetallic nanotemplates. The kinetics of electroless copper deposition (ECD) catalyzed by these bimetallic nanoplates are analyzed by using a quartz crystal microbalance (QCM). The results reveal that Ag18Pd1 nanoplates show better catalytic activity than Ag18Pd1.5 and Ag18Pd2 nanoplates. Further, the catalytic activity of the porous nanoplates in the ECD bath can be controlled by varying their alloy ratios. [Copyright &y& Elsevier]