| Monolithic honeycomb catalysts are widely used not only in the conventional environmental protecting field, such as automobile exhaust and industrial waste gas, but also in the area of new energy producing and energy-saving & emission-reducing in recent years. Using noble metal-transition metal/Al2O3/cordierite as a model catalyst for PTA exhausted gas removal to study the process conditions and process parameters of monolithic catalysts during preparation, including impregnation, drying as well as calcinating steps. The results provide theoretical and technical support for industrialization of monolithic catalysts.The impacts of different active factor loading and different impregnation methods are investigated firstly. Then the study is emphasized on the effects of impregnation conditions on the adsorption capacities of Pt(Ⅳ), Pd(Ⅱ) and Mn(Ⅱ) over y-alumina-coated cordierite honeycomb under excessive impregnation. The impregnation conditions include pH, temperature and concentration of impregnating solution. The adsorption kinetic curves of different components are fitted with both Lagergren first order model and Lagergren second order model. The adsorption isotherms have also been analyzed using Langmuir and Freundlich models respectively. The fill-in rate of solution (tf), capillary permeation rate(τc), diffusion rate of solute in solvent in honeycomb (tF), diffusion impregnation rate in the micropore of y-Al2O3 (τd) and adsorption rate in the experiment (ra) have been calculated respectively. The results reveal that the impregnation of Pt(Ⅳ), Pd(Ⅱ) and Mn(Ⅱ) on the monolithic support is kinetically controlled. The calculation and comparison of water evaporation rate js at both ends of the cellular carrier, diffusion rate of water molecules within the cellular pore jc, solute migration rate jt, as well as the EDS characterization are studied. It is found that rapid drying is more suitable for evenly distribution of active factors compared to slow drying by step. Calcination temperature and time are also researched, and the optimum calcination temperature and time are obtained by comparison.The results showed that the optimal temperature of Pt(Ⅳ), Pd(Ⅱ) and Mn(Ⅱ) impregnation are 80℃, optimal pH are 4.13 for Pt(Ⅳ),4.53 for Pd(Ⅱ) and 1.00 for Mn(Ⅱ). It is showed that Lagergren second order model fits more properly with Pt(Ⅳ), Pd(Ⅱ) and Mn(Ⅱ) adsorption curves than Lagergren first order model. It can be also concluded that the adsorption of Pt(Ⅳ), Pd(Ⅱ) and Mn(Ⅱ) on the honeycomb complies with Langmuir monolayer adsorption mechanism. The water evaporation rate js at both ends of the cellular carrier is far slower than diffusion rate of water molecules within the cellular pore jc, but much faster than solute migration rate jt. The optimum condition for calcination is to calcinate two hours at 470℃.Monolithic honeycomb in larger size has been prepared under all the optimum conditions. The activity tests have been done in industrial sidetrack. Fresh and used monolithic catalysts are investigated and compared by using XRD,BET,SEM,XPS,XRF,EDS and CO-TPD characterization to study the impaction during the use in industrial reaction.
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