Preparation And Study Of Complex Photocatalyst Honeycomb Without Sintering

The direct catalysis method is the most promising technology in dry desulfurization and denitration technologies.Catalyst honeycombs are key materials in the technology,and need to be sintered at high temperature to meet the need of the product strength.But the high temperature sintering should reduce the catalytic activity,and consume power sources.So,it is an important project in the low carbon economy and environmental protection to find new technology that has lower energy expending and high photochemical catalysis feature.In this research,TiO2 catalyst honeycombs without sintering were prepared via kneading,mulling,extrusion molding and solidifying at room temperature with the magnesite oxychloride gels modified by nano rice husk ash(RHA)as a solidifying agent.Samples properties were characterized by XRD,SEM,EDS,XPS,bending test and the calculation of softening coefficients.This study showed that:RHA was prepared by self-propagating low-temperature synthesis and the burn temperature was studied minutely in this experiment.The particles size of RHA prepared under a 550℃ temperature for four hours was about 50nm,the reunion problem was unconspicuous and the content of amorphous state SiO2 reached 92%meanwhile.SiO2 can combine with Mg(OH)2 and generate Mg2SiO4 and 2Mg0 SiO2 H20,thus the anchoring strength and compactness of Magnesium-Oxychloride were strengthened and hydrolysis of 5·1·8 phase was weakened.With 15%RHA and 2.0%complex water-resistance added together,the soften coefficient of magnesite materials could reach up to 0.97.The flexural strength of unsintered catalyst honeycombs that were prepared with 4:1 ratio of TiO2 and MgO could reach 9.41 Mpa in this experiment.The 5·1·8 phase dispersed in TiO2 granules and played a solidifying role.The activity SiO2 in RHA could increase the specific surface area、surface defect and energy gap of TiO2 crystal,thus the photocatalysis of TiO2 was improved;it was favorable to the desulfurization and denitrification since that the Mg(OH)2 in Magnesium-Oxychloride could absorb SO2 and NO2 easily;in the meantime,a few Mg2+ could break the lattice structure of TiO2 and increase its surface defect while being beneficial to the enhance of TiO2’s photocatalysis.Unsintered catalyst honeycombs had an excellent degradation effect on methyl orange.With in 4.5 hours under UV-irradiation it could eliminate 98%of the SO2 and 65%of the NO2,while under visible light 88%of the SO2 and 42%of the NO2 eliminated.