Catalytic selective reduction of NO with propylene over Cu-Al2O3 catalysts: influence of catalyst preparation method

Bulk and Surface Properties of Dispersed CuO Phases in Relation with Activity of NO x Reduction

“…Catalysts based on finely divided copper oxide have displayed interesting activity towards total oxidation of CO, [6][7][8], hydrocarbons [6,9] and alcohols [10,11], and NO x , and SO 2 reduction reactions [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. In the case of selective catalytic reduction of nitrogen oxides (NO x ) by hydrocarbons in an oxygen-rich atmosphere, (HC-SCR process), various catalytic systems based on CuO dispersed with different methods on supports of different nature have been successfully reported in the literature [17][18][19][20][21].…”

“…Ion-exchange method, even if it is able to stabilize copper species assuring good dispersion, cannot be widely used because of the low loading of copper obtained due to the limit terminal -OH groups on the oxide surfaces. To obtain higher copper loading and stability of the copper species, grafting or chemisorption methods of deposition could be pursued [19,24]. Recently, our research group has used silica based oxides as supports for copper deposition by chemisorption-hydrolysis method [20], demonstrating its suitability in dispersing CuO in nanosized aggregates even for high copper loading (up to 9 wt% of CuO).…”

<b>THE INFLUENCE OF TRANSITION METALS ON THE PERFORMANCE OF Pt Rh Pd/&gamma;-AL₂O₃ THREE WAY CATALYSTS FOR PURIFICATION OF AUTOMOTIVE EXHAUST GAS</b>

“…The TPR profile of reference CuO/γ-Al 2 O 3 exhibits peaks at 613 and 713 K originating from the two-step reduction of the Cu 2+ ion to metallic copper [23]. The TPR profile of the CuO/γ-Al 2 O 3 shows two peaks at about 539 and 679 K. According to the literature [24][25][26], the low temperature peak might be assigned to the reduction of several highly dispersed copper oxide species. The high temperature peak might be attributed to the reduction of the supported Cu + ions (arising from partial reduction of isolated Cu…”

“…) to Cu 0 [24,26]. There are three peaks in the TPR curve of Pt Rh Pd/γ-Al 2 O 3 and Pt Rh Pd-1.56 mol% CuO/γ-Al 2 O 3 catalysts, the main reduction peak for the above two catalysts is located at 773 K. Compare with the TPR peaks at 595 K and 846 K of Pt Rh Pd/γ-Al 2 O 3 catalyst, the reduction peaks of Pt Rh Pd-1.56 mol% CuO/γ-Al 2 O 3 catalyst moved forward, which can be attributed to the addition of copper.…”

Catalytic performances of CuGa and CuSn binary oxide catalysts towards N2O decomposition and reduction

“…CuO is one of the most studied and active transitional metal oxides in the NO x abatement, its catalytic potentialities and also its limits have been clearly shown in the literature since two decades [17,[54][55][56][57][58][59][60][61][62]. Therefore, new catalytic formulations are searched by coupling Cu oxide with other transitional oxides for widening the activity temperature interval, improving selectivity, increasing turnover frequencies, etc.…”