Synthesis And Property Of Novel Ordered Nanostructure Integrated Monolithic Catalyst In Diesel Engines Exhaust Purification

With the increasing amount of automobiles around the world,vehicle exhaust emission including carbon monoxide(CO),hydrocarbon(HCs),nitrogen oxides(NOx)and particulate matter(PM)is becoming the major source of air pollutants especially in mega cities,which had caused severe problem to human health and environmental sustainability.How to reduce harmful emissions from vehicle exhaust has become one of the primary problems in automotive industry.Catalytic conversion technology is one of the most effective ways to control vehicle exhaust emission.The commercial three-way catalyst(TWC)formulation usually contains noble metals as the active components,such as platinum(Pt),palladium(Pd)and rhodium(Rh).However,noble metal is getting more and more expensive due to its widely application but limited reservation.Recently,developing a catalyst with lower noble metal loading but better catalytic activity and stability is an important topic for both academia and industry.The 3D honeycomb ceramic with high mechanical strength,higher porosity and small exhaust flow resistance has been widely used in automobile exhaust purification catalyst as support.High surface area catalysts are then loaded on 3D honeycomb substrate to make an effective monolithic catalyst.Recently,novel ordered nanostructure integrated monolithic catalysts have shown great promise in energy and environmental applications.Based on the concept,firstly,we successfully prepared TiO2-Al2O3 binary nanoarray grown onto the 3D channel surfaces of ceramic honeycombs by a facile one-pot hydrothermal method.The nanoarrays are composed of anatase-TiO2 and mesoporous?-Al2O3,which grows densely and uniformly on the substrate.With well-tuned size and shape by temperature and reaction time,the TiO2-Al2O3 binary nanoarray exhibits excellent robustness under mechanical vibration,thermal,and hydrothermal aging.Moreover,the Pt/TiO2-Al2O3 binary nanoarrays catalyst for propane conversion reaches rapidly to 80%at temperature as low as 224?,which suggests the catalyst is a promising candidate for practical application.In addition,by using the diesel particulate filter(DPF)as support,we also in-situ grew 3DOM Ce1-xZrxO2 catalyst on the channel surface by PS self-assembly template methods.This study found that the 3DOM catalyst with well controlled pore structure,has higher specific surface area,good mechanical stability,and excellent soot combustion characteristic.