Development Of Structured Catalysts For Catalytic Decomposition Of Gaseous Pollutants And Study On Electrothermal Synergies

Ozone catalytic oxidation is an advanced technology for the treatment of volatile organic compounds（VOCs）in gaseous pollutants,but the problem of excessive ozone during using still needs to be solved.Due to its unique pore structure,Mn polyvalent state and oxygen vacancy,OMS-2 has been widely used in the purification of VOCs and O₃ by catalytic oxidation.However,powder catalyst is difficult to be used directly,and honeycomb or particle catalysts prepared by traditional methods have problems such as low utilization rate and poor strength.Therefore,an integral catalyst with high specific surface area,reasonable pore distribution and good mechanical strength is urgently needed.In this paper,OMS-2 powder was used to prepare ceramic foam monolithic catalyst and nickel foam monolithic catalyst,and the influence of electrothermal synergy effect on catalyst performance was studied.Firstly,OMS-2 synthesized by hydrothermal method,then modified the pH of the solution with H₂SO₄ and doped with Ce element,and successfully synthesized the rod-like Ce-OMS-2 with a length of 50-100 nm and a diameter of 10-20 nm,with a specific surface area of about 178.43 cm²/g.The catalytic performance of ozone increased from over 90%in 6 h to 100%in 12 h.After the organic foam polyurethane was treated with NaOH,JN30,PVA and other reagents,the slurry hanging amount increased from18.1 g/g to 26.8 g/g,the slurry ratio and sintering system were optimized and sintered at 800℃to obtain a porous foam ceramic monolithic catalyst with a through porosity of 70%and a mechanical strength of 0.76 MPa,and the catalytic efficiency for ozone remained 99%within 6 hours.Secondly,35 ppi nickel foam was selected as catalyst carrier,the surface roughness of nickel foam was improved by HNO₃ treatment,and the impregnation process was optimized to obtain a monolithic nickel foam catalyst with a loading capacity of 35%,mechanical strength of 1.58 MPa and through-pore rate of 85%.Moreover,the catalytic efficiency of nickel foam for ozone was 100%within 6 h.Compared with the pure ozone oxidation of toluene,the treatment efficiency was increased from 25%to 55%;In the electrothermal catalytic experiment,the catalytic conversion rate of the catalyst for ozone was increased to 100%within 24 h,and the catalytic efficiency of the catalyst for ozone was increased from 90%within 2 h to 100%within 24 h under the condition of 90 RH%.The treatment efficiency of p-toluene was increased from 55%to 100%.Compared with the traditional heating method,electrothermal catalysis can save 13-15%energy,which proves the feasibility of electrothermal catalysis.