Enhanced decomposition of no on the alkalized PdO/Al2O3 catalyst

Understanding the chemical state of palladium during the direct NO decomposition – influence of pretreatment environment and reaction temperature

“…For instance, the performance of supported noble metal catalyst, which is the commercialized component of three-way catalyst, was only addressed in a few reports for direct NO decomposition. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Pt based catalysts were investigated in early 20 th century and found out that the catalysts deactivates quickly at lower temperatures. [16][17][18][19] Recently, studies have been focused on investigating palladium based catalysts for direct NO decomposition because of its better thermal stability and low cost compared to Pt based catalysts.…”

“…[16][17][18][19] Recently, studies have been focused on investigating palladium based catalysts for direct NO decomposition because of its better thermal stability and low cost compared to Pt based catalysts. [20][21][22][23][24][25][26][27][28][29][30] Most of the reports concentrated on the performance of supported palladium catalyst in direct NO decomposition at various reaction temperatures (from 300 C to 900 C). [20][21][22][23][24][25][26][27][28][29][30] However, a very deep understanding about the function and chemical state of the palladium during direct NO decomposition at different reaction temperatures has not been attained.…”

“…[20][21][22][23][24][25][26][27][28][29][30] Most of the reports concentrated on the performance of supported palladium catalyst in direct NO decomposition at various reaction temperatures (from 300 C to 900 C). [20][21][22][23][24][25][26][27][28][29][30] However, a very deep understanding about the function and chemical state of the palladium during direct NO decomposition at different reaction temperatures has not been attained. For example, Baibich group [26][27][28][29] evaluated several supported and bimetallic Pd catalysts for direct NO decomposition and reported that metallic Pd catalysts deactivate with time irrespective of support and foreign metal.…”

Microwave Irradiation Coupled with MeOx/Al2O3 (Me=Cu, Mn, Ce) Catalysts for Nitrogen Monoxide Removal from Flue Gas at Low Temperatures

“…Among various NO x removal routes, the direct catalytic decomposition of NO into N 2 and O 2 offers the most ideal and attractive route to removing NO with respect to economic and environmental considerations, as it also does not involve addition of toxic reducing agents (such as ammonia) and the products of this reaction are environmentally friendly . Several catalysts have been proposed for the direct decomposition of NO in the conventional reaction mode (CRM), including noble metals, metal oxides, and metal‐ion‐exchanged zeolites . Unfortunately, these catalysts cannot be applied practically to exhaust conditions.…”

“…[2] Amongv arious NO x removalr outes,t he direct catalytic decompositiono fN Oi nto N 2 and O 2 offers the most ideal and attractive route to removing NO with respectt oe conomic and environmental considerations,a si ta lso does not involve additiono ft oxic reducing agents (such as ammonia) and the productso ft his reactiona re environmentally friendly. [3,4] Several catalysts have been proposed for the direct decomposition of NO in the conventional reaction mode (CRM), including noble metals, [5][6][7] metal oxides, [8][9][10][11][12][13] and metal-ionexchanged zeolites. [14][15][16] Unfortunately,t hese catalysts cannot be applied practically to exhaustc onditions.C u-ZSM-5, one of the most active catalysts for the direct decomposition of NO in the CRM, has al ow hydrothermal stability and becomes deactivated at temperatures higher than 600 8C; noble-metal catalysts are also expensive and strongly inhibited by the presence of oxygen.…”