The Study On Catalyst Performance Of Carbon Dioxide Reforming Of Methane Reaction Of Mesoporous Molecular Sieve Skeletal Modified Ni/Mo/SBA-15

Human under the condition of the symbiosis with nature in order to seek the faster development,also made a series of environmental problems unconsciously,the people more and more attention to environmental problems in modern society,the bad effects of the greenhouse effect has been cannot be ignored.In order to improve the environment,the greenhouse gas emissions has to limit,in addition the researchers also in actively looking for some ways to make use of greenhouse gas.Carbon dioxide reforming of methane reaction began in 1928,Fischer and other scholars did a lot of experiments on this reaction,since then it has attracted the interest of a growing number of researchers,they found a large number of theory and practice research on catalyst on the reaction system.These two The CH₄ and CO₂ are two kinds of main greenhouse gas who caused the greenhouse effect,The reforming reaction can use CH₄ and CO₂ at the same time.Synthetic products are also gas,the 1:1 proportion about CO and H₂.And ethanol,methanol and other chemical products used widely,even F-T synthesis can be the syngas as materials,and the effect is very well.Therefore,CH₄ and CO₂ reforming reaction can effectively reduce the greenhouse gas,improve the living environment of the surrounding and can reduce waste at the same time.As a kind of good catalyst carrier,SBA-15 mesoporous molecular has bigger sievesaperture,but it not the only advantage,besides it also has thick bore wall,entrance and higher surface area,better thermal stability,the most important is it create simple,spend low cost,non-toxic and harmless,it is very environmental.In this paper using the SBA-15mesoporous molecular sieve as catalyst carrier,high dispersion of nickel-based catalysts was prepared.Mainly studied the skeleton modified mesoporous molecular sieve SBA-15 and additives on the properties of catalytic carbon dioxide reforming of methane.In Ni/Mo/SBA-15 bimetallic catalyst,the main evaluation of the stability of the catalyst and catalytic activity;By use of XRD,SEM,FTIR method for modification of catalyst characterization synthetically.The main research results are as follows:By hydrothermal synthesis method of preparation of the various series catalyst,under the standard atmospheric pressure,reaction temperature is 800?,GHSV=1.2×l0⁴ ml g^-1_cath^-1,V?CH₄?/V?CO₂?=1:1 catalyst evaluation on the catalytic reaction conditions.?1?In the Ni/Mo/CeO₂/Al-SBA-15 and Ni/Mo/La₂O₃/Al-SBA-15 series of catalyst evaluation,Ni/Mo/CeO₂/Al-SBA-15 has consecutive 80h of CO₂ conversion as high as 97%above,CH₄ conversion rate has remain 90%above until 50h.Ni/Mo/La₂O₃/Al-SBA-15catalyst has a high initial reactivity,conversion rate reached 94%,but in the third hour fell to89%,and stable in more than 80%until 72h.72h-98h conversion rate gradually decreases below 70%.And reaction after FT-IR results shows that the structure of mesoporous materials already damaged seriously,catalyst support structure has been burning under the high temperature,so weaken the catalytic effect.In introducing the La₂O₃ and CeO₂ catalyst,can form solid solution related Mo_xLa_1-xO₃ and Mo_xCe_1-xO₂,enhance the performance of the catalyst.?2?Ni/Mo/CeO₂/La-SBA-15 and Ni/Mo/ZrO₂/La-SBA-15 series catalyst in the evaluation of Ni/Mo/CeO₂/La-SBA-15 in the conversion of CH₄ and CO₂ conversion rate,all showed higher conversion rate and longer catalyst life than the latter,it showed better catalytic performance and stability.On both before or after the stability test of the mesoporous material structure to maintain relatively intact,the deformation of tunnel collapse is not seriously.Introducing the CeO₂ catalyst,has formed a solid solution Mo_xCe_1-xO₂,the compounds as part of the solid particles is very fine and exquisite,it can improve the dispersion degree of active ingredients.Ni/Mo/ZrO₂/La-SBA-15 catalyst keep more than 90%of the time nearly 40h of high methane and carbon dioxide conversion,it also is a good catalyst.This is because the ZrO₂ has very good oxygen exchange ability,oxygen enrichment of ZrO₂ between ZrO₂ lean oxygen circulation,speed up the lattice oxygen exchange between ZrO₂ and Mo,prevents MoO₂reduction in the process of reaction,and thus maintain a higher activity and stability of the catalyst.?3?Ni/Mo/Pd/La-SBA-15 and Ni/Mo/Pd/Al-SBA-15 series in the evaluation of these two kinds of catalysts,Ni/Mo/Pd/La-SBA-15 can be kept more than 95%of CH₄ conversion rate to 216h,it kept high CO₂ conversion continued nearly 240h before the catalyst in the reaction experiment has remained above 90%,and at 250h still maintained 85%conversion rate.Ni/Mo/Pd/Al-SBA-15 catalytic activity and stability are also very well,the CH₄conversion rate from 95%to 100%range within the scope kept nearly 73h,CO₂ conversion rate from 95%to 100%range within the scope of nearly 70h,it also has excellent catalytic performance and long life.It can be say this two kinds of catalysts are reflected the precious metals excellent catalytic performance.La can be directly introduced into molecular sieve skeleton of channel structure,so that the molecular sieve has a larger specific surface area and entrance,and other auxiliary metal dispersion is greatly increased in the carrier,so it made the catalyst has higher catalytic activity.