•Cu2+ and Zn2+ precipitate in microchannel reactor.•Homogenous Cu, Zn distribution leads to more Zn2+ ions incorporating into the malachite.•More intimate contact and stronger interaction of Cu and Zn survives after calcination and reduction.•Catalyst manifests higher activity for methanol synthesis.Cu/ZnO catalyst was prepared by co-precipitation method inside microchannel reactor and characterized by X-Ray diffraction (XRD), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The XRD analysis of precursors demonstrates that, compared with the sample prepared by conventional batch reactor, more Zn2+ are incorporated into malachite structure, which is attributed to the relatively uniform distribution of Cu, Zn elements in initial precipitates caused by the excellent mixing performance of the microchannel reactor. Higher decomposition temperature of carbonate species trapped in the interfaces between CuO and ZnO and higher binding energy of Cu2p3/2 indicate that sample prepared by the new reactor possess a stronger interface interaction, which derives from the more intimate contact between oxide components. This supposition is confirmed by the HRTEM images and the stronger interface interaction in the final reduced catalyst can improve catalytic performance on methanol synthesis.more intimate contact between oxide components in MR-Oxide.

•The low-temperature activity of Au–CeO2 catalyst in benzene oxidation depended mainly on the microstructure of CeO2.•The red-shift of F2g band of CeO2 in Raman spectroscopy presented an obvious relevance with the low-temperature activity.•The red-shift of F2g of Au–CeO2 catalyst prepared by Adsorbed-Layer Reactor Technique changed with the amount of NaOH pre-addition in preparation.•The doping of other metal ion could change F2g and low-temperature activity.Au–CeO2/SiO2 catalysts were synthesized by Adsorbed-Layer Reactor Technique and characterized by TEM, XRD and Raman spectroscopy. It was found the pre-addition of NaOH changed the hydrolysis of HAuCl4 in adsorbed layer and then regulated the morphology and microstructure of Au and CeO2. In the catalysis of benzene oxidation, with the increase of pre-addition amount of NaOH, the high-temperature activity increased monotonously, which was consistent with the change of crystallite size of Au. However, the low-temperature activity presented a maximum with increase of pre-addition amount of NaOH, which was verified being agreement with the change of red-shift of F2g peak of CeO2. The results showed that the high-temperature activity depended on Au size and the low-temperature activity was affected by CeO2 microstructure. The experiment of metal ion doping offered another proof.The low-temperature activity of benzene oxidation on Au–CeO2/SiO2 and the red-shift of F2g peak of CeO2 presented a similar tendency with increase of pre-addition amount of NaOH.

Au nanoparticles were supported on modified SiO2 via adsorbed-layer nanoreactor technique. The morphology of the catalysts was analyzed by TEM, and the grain size of Au was determined by X-ray diffraction. Owing to the higher isoelectric point (IEP), the modifying component was significantly helpful for the preparation of much smaller Au nanoparticles on silica. However, the size order of Au was different with the order of IEP of modifying component. The catalysts showed an apparent Au particle size-dependent activity on the oxidation of cyclohexane. The catalyst modified by Ni(OH)2 with the smallest Au particles had the highest catalytic activity, while it had the lowest one when modified by Mg(OH)2 with the biggest Au particles. The selectivity to cyclohexanol and cyclohexanone could maintain at a high value as the conversion increased, which was different from the results of catalysts prepared by other routes.

TiO2/SiO2 was prepared by adsorption phase synthesis, and its photocatalysis on degradation of gaseous toluene was studied. The concentration of water added in preparation and temperature in calcination were changed to regulate formation of anatase TiO2. Ti contents in samples and grain size of anantase TiO2 were measured, and the catalytic activity in photodegrading gaseous toluene was characterized. The photocatalytic activity increased sharply when the calcination temperature increased to 500 °C or the volume of water added in preparation reached 1.5 mL. XRD analysis indicated that the crystal phase transformation of TiO2 from anatase to rutile was restrained and TiO2 remained in the form of anatase even after being sintered at 900 °C. The high constant photocatalytic activity from 500 to 900 °C was attributed to the stability of anatase TiO2 in crystal size and phase transformation.

Three reaction systems were selected to investigate the influence of reactants distributed in a bulk or in an adsorption layer on the preparation of silver nanoparticles. Reactant distribution in three systems was measured by iodometric, Volhard's and conductivity methods, respectively. Results show that the reactants in system I and II both distributed mainly in the bulk and the adsorption layer could not affect the reactant distribution. In system III, both the formation and the change of the adsorption layer could influence much on the reactant distribution. When the adsorption layer formed gradually in system III, mass percent of NaOH adsorbed on SiO2 changed from 25 to 60%. With amount of reactant in the adsorption layer increasing, reaction region transferred gradually from the bulk to the adsorption layer, which led to more homogeneous Ag particles with smaller size on SiO2 surface. Due to the significant inhibition of the nanoreactor, the size of Ag particles grew in the adsorption layer was below 5 nm.

The formation mechanism of Ag in an adsorption layer and the influence of temperature on the generation of Ag particles were studied. Two reaction systems were designed to explore the different reduction mechanisms of Ag+ in an adsorption layer and in bulk. A UV−vis adsorption spectrometer was employed to monitor the reaction process of Ag+ in two reaction systems. The results indicated that the formation mechanism of silver in an adsorption layer was largely different from that in alcohol bulk, which led to various morphologies of Ag particles in the two systems. Temperature experiments suggested that the induction time and morphology of Ag particles both changed greatly when temperature increased to 40 °C. The disappearance of physical-adsorption and the reaction occurring in alcohol bulk was the primary cause.