Hua Deng
Institute of Urban Environment, Chinese Academy of Sciences, China
Title: Preparing Ag/Al2O3 catalyst with AlN addition to improve the low temperature reduciton activity of NOx by ethanol
Biography
Biography: Hua Deng
Abstract
NOx removal from lean-burn exhaust remains a major challenge in environmental catalysis. Selective catalytic reduction of NOx by hydrocarbons (HC-SCR) is a potential method to remove NOx from lean-burn exhausts. The alumina supported silver catalyst (Ag/Al2O3) is deemed as one of the most effective materials for HC-SCR of NOx in excess oxygen. In particular, ethanol is extremely effective for the SCR of NOx over Ag/Al2O3. However, it is lack of activity in the low temperature range (< 350 ℃) still remains a problem. Since pioneer work of Burch et al, preparing a new type of Ag/Al2O3 catalyst to improve its low temperature performance by solvent-free mechanochemically method draw widely interest. In former study, the detailed preparing conditions including rotation speed and ball-milled time were carefully examined. The performance of selective reduction of NOx was evaluated by ethanol accompanied with byproduct monitor. A strongly positive correlation between the amount of Altetra structures and N2 production rate confirms the crucial role of Altetra in NOx reduction by ethanol. Thus, oriented designing and creating active site of HC-SCR( namely Ag-O-Altetra entity) at micro-scale in Ag/Al2O3 is promising to improve the conversion activity at low termperatures. In this study, AlN was used as precursor of Altetra entities to anchor isolated silver ions. After water thermal calcination of Ag/Al2O3 with AlN addition, the low temperature activity is truely improved. The catalytic performance of this catalysts is close to the H2 effect.