Wet impregnation method

Preparation conditions of Pd/CNFs by wet impregnation method, such as palladium precursor, impregnation time, calcinations and reduction, are proved to have profound effect on the catalytic property. The catalyst prqjared by impregnating HzPdCLi precursor in an hour, then calcinated in air and reduced in 20%H2/Ar is believed to perform better in CTA hydropurification than the industrial Pd/C under laboratory conditions. 

The NH4-Y (CBV712, ao = 24.35 A), H-Beta (CP811E-75), NH4-Beta (CP814E) zeolites were obtained from Zeolyst International. The NH4-Y and Beta zeolites were transformed to proton forms through step calcination procedure in a muffle oven. Zeolites containing 1 wt-% platinum were prepared by wet-impregnation method using hexachloroplatinic acid as the Pt-source. 

For this purpose, all three catalyst supports were initially synthesized by a chemical vapor deposition (CVD) process and thereafter, using a wet impregnation method, loaded with cobalt as the active component for FTS. The as-synthesized Co/nanocatalysts were then characterized by applying electron microscopic analysis as well as temperature-programmed desorption, chemi- and physisorption measurements, thermogravimetric analysis, and inductively coupled plasma... 

Similar procedures adopted for the synthesis of TS-1 (the mixed alkoxide method, dissolved titanium method, pre-hydrolysis method, wetness impregnation method, and promoter induced synthesis method) were also used for the synthesis of TS-2. Tetrabutylammonium hydroxide (TBAOH) instead of TPAOH was used as the template (6,7,305-308). 

OH ratio on the rate of crystallization and crystallite size investigated Prehydrolysis method. Synthesis using binary mixtures of tetrabutylphosphonium hydroxide and tetraethylphosphonium hydroxide instead of TPAOH as base and template TEOS and TBOT are sources of Si and Ti, respectively. Molar gel composition, SiO2 xTiO2 0.4 ( TEPOH + (1 — jd)TBPOH) 30H2O (x = 0-0.02) temperature = 443 K and synthesis time = 4 days Influence of nature of silicon and titanium alkoxides on the incorporation of Ti Wetness impregnation method... 

Mixed alkoxide method. Synthesis using TPAOH and HF and wetness-impregnation method using TPABr and NH4F... 

Catalysts were prepared by wet impregnation method. Among them, Ni/La203 exhibited high activity and selectivity for H2 production in the SRE reaction. The enhanced activity has been attributed to scavenging of coke deposited on the Ni surface by lanthanum oxycarbonate species... 

Navio, J.A., G. Colon, M. Trillas, J. Peral, X. Domenech, J.J. Testa, J. Padron, D. Rodriguez and M.I. Litter (1998). Heterogeneous photocatalytic reactions of nitrite oxidation and Cr(VI) reduction on iron-doped titania prepared by the wet impregnation method. Applied Catalysis B-Environmental, 16(2), 187-196. 

Two medium-pore zeolites, namely, ferrierite (Si/Al = 6.3) and theta-1 (Si/Al = 30) were used in this work. They were used as catalysts in the H-form or were modified by gallium before catalytic experiments. In the latter case, Ga was introduced into the zeolites by an incipient wetness impregnation method, using aqueous solutions of Ga(N03)3. In this work, catalysts with a Ga content of 2.2 wt.% were investigated. 

Activated carbon modified chemically with potassium hydroxide via low temperature wet impregnation method for NOx adsorption was used. The present study examined adsorption and desorption behaviors and the accompanied surface chemistry. In particular, typical desorption behavior was examined after NOx was adsorbed at 100°C while the temperature was increased up to 600°C. This study found that the presence of a relatively larger amount of adsorbent delays surface oxidation. NOx has become oxidized while inducing three types of physical and chemical bonds on the surface of BHAC. The results concerning the surface properties after adsorption and desorption were analyzed using various instruments. Potassium existed on the surface without consumption as K-IAC was adsorbed by potassium oxide after desorption. 

The impregnation method is convenient to disperse a small amount of well-fine particles on the surface of the support. An amount of supported particles depends on the concentration of the solution and pore volume of the support. Incipient wetness impregnation method is also used for precious control of the amount of the deposition. After evacuation of the support the solution coircsponded to the pore volume is added little by little and the surface of the support uniformly gel wet. 

Sc, Al, Th Zr", and Si, have been prepared according to the wetness impregnation method to investigate their effects on thermal stability of ceria. These impregnation methods are. of course, useful to synthesize ceria-based oxides supported on another oxides such as silica and alumina. The most advantage of the method is that highly dispersion is obtained. 

The results presented here demonstrate that well-defined model catalysts with particle sizes in the 10-100-nm regime can be efficiently processed with lithographic methods. These model catalysts possess most of the desirable characteristics that are required in fundamental heterogeneous catalysis research. There are considerable advantages, compared to model catalysts prepared by, e.g., incipient wetness impregnation methods, which are enumerated ... 

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