WO3/CeO2-ZrO2, a promising catalyst for selective catalytic reduction (SCR) of NOx with NH3 in diesel exhaust

Abstract

A WO3/CeO2-ZrO2 catalyst system was discovered for selective catalytic reduction of NOx with NH3; the catalyst (10 wt% WO3 loading) showed nearly 100% NOx conversion in a temperature range of 200-500 degrees C, at a space velocity of 90 000 h(-1) in a simulated diesel exhaust containing 550 ppm NOx (NO : NO2 feed ratio at 1.0), 10 vol% H2O and 10 vol% CO2; the catalyst also exhibited high temperature stability.

Effect of the calcination temperature on the performance of a CeMoOx catalyst in the selective catalytic reduction of NOx with ammonia

“…Normally, the temperature of the exhaust gas from diesel engine ranges from 150 to 500 • C [6]. However, this temperature can be higher under certain conditions [26]. For the practical use, the sudden change in temperature of the catalyst brick for diesel engine exhaust gas converter may happen and may lead to the structural and performance change of the catalyst [22].…”

Effect of the Mn oxidation state and lattice oxygen in Mn-based TiO2 catalysts on the low-temperature selective catalytic reduction of NO by NH3

“…SCR reactors at power plants and gas turbines can be located in the later portions of the dust collection and desulfurization devices to avoid deactivation from dust or SO 2 . At this point in the process, the temperature is less than 200 C, which is where the conventional V/W/TiO 2 catalysts used in the NH 3 -SCR process cannot be used (Kuo et al, 1997;Li et al, 2008). Accordingly, a denitrification catalyst is required for successful SCR operation at temperatures under 200 C. In this temperature range, MnO x -based catalysts are suitable for the NH 3 -SCR system.…”

An environmentally-benign CeO2-TiO2 catalyst for the selective catalytic reduction of NO with NH3 in simulated diesel exhaust

“…Some vanadium-free transition metal-based oxide catalysts, such as FeTiO x [16][17][18], CuO x /WO x -ZrO 2 [19], and WO 3 /CeO 2 -ZrO 2 [20], have also been reported as potential substitutes of vanadiumbased catalysts for diesel vehicles. Nevertheless, these catalysts have been mainly tested under relatively low GHSV (<100,000 h −1 ).…”