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Catalytic elimination of environmental pollutants, such as nitrogen oxides, carbon monoxide, sulfur compounds, chlorinated and other organic compounds, and soot emitted from stationary or mobile sourcesBasic understanding of catalysts used in environmental pollution abatement, especially as applied to industrial processesAll aspects of preparation, characterization, activation, deactivation and regeneration of novel and commercially applicable environmental catalystsNew catalytic routes and processes for the production of clean energy, such as in hydrogen generation via catalytic fuel processing; and new catalysts and electrocatalysts for fuel cellsCatalytic reactions in which wastes are converted to useful productsClean manufacturing replacing toxic chemicals with environmentally friendly catalystsScientific aspects of photocatalytic processes and basic understanding of photocatalysts as applied to environmental problemsNew catalytic combustion technologies and catalystsNew catalytic non-enzymatic transformations of biomass components The journal will accept original Research Papers, Reviews and Letters to the Editor. Papers dealing with reactions and processes aimed at the production of commercial products and the remaining aspect of catalysis should be directed to Applied Catalysis A: General. Enzymatic papers should be directed to Journal of Molecular Catalysis B.

The deactivation and regeneration of selective catalytic reduction (SCR) catalysts poisoned by potassium by a wet-impregnation method was investigated experimentally. Potassium in the form of both chloride and sulfate is a strong poison for the catalyst. The results indicate that potassium titrates the active sites for NH 3 adsorption. Simply increasing the operating temperature or the vanadium content in the catalyst cannot compensate the loss of catalyst activity: Increasing the temperature hardly increases the conversion of NO for the strongly poisoned catalysts, and catalysts with high vanadium content become active for oxidizing NH 3 to NO, causing a net NO formation. Deactivated catalysts can be regenerated by different methods. Sulfation by gaseous SO 2 is efficient provided the poison is first removed by washing. When regenerating by 0.5 M H 2 SO 4 , the catalyst regains a higher activity than that of the fresh catalyst at temperatures higher than 300 °C. Heat treatment of the catalyst at 400 °C for 2 h after poisoning to simulate actual operation has no influence on the regeneration by 0.5 M H 2 SO 4 . Deactivated catalysts without the heat treatment step regain higher activities than that of the fresh catalyst at all temperatures when regenerated by 1 M NH 4 Cl. However, the heat treatment step has a negative effect on the regeneration by NH 4 Cl.

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The kinetics of NO reduction over wheat straw char in the presence and absence of CO was investigated in a laboratory scale fixed bed quartz reactor. Experiments were performed with char from both the raw straw and from washed straw. The wash procedure removed most of the content of potassium and other catalytic species in the straw. The temperature was in the range 600−900 °C, the NO concentration was in the range 50−1000 ppmv, and CO was in the range 0−5 vol %. The char from raw straw was more active than the washed char by up to a factor of 2.5, but both chars were found to be very active compared to the activity of coal chars reported in the literature. At temperatures above about 850 °C the difference in reactivity decreased between the two straw chars, probably because the catalytic species in the char from raw straw was vaporized and/or reacted to form catalytically inactive potassium silicates. The reaction order for NO was about 0.7 independent of temperature for both chars. The rate expressions for NO reduction over chars from raw and washed straw respectively are the following:  −r NO = 2.06 × 105 × exp(−16180/T) × mol kg-1 s-1, and −r NO = 9.53 × 104 × exp(−15950/T) × mol kg-1 s-1. The addition of CO resulted in an immediate increase in the rate of NO reduction, but the rate decreased over time and could in some cases stabilize at a level similar to that when CO was absent. This effect is not understood in detail. A reaction mechanism for reduction of NO over char is proposed and discussed.

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