1990s, scientists Mobile Oil company invented the capillary material medium M41-S, the introduction

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1990s, scientists Mobile Oil company invented the capillary material medium M41-S, the introduction of these materials creates a strong breakthrough in the field of materials science catalytic . MCM-41 materials as their representative average capillary material, there are many applications in chemical tools and equipment in food preservation process technology, petrochemicals.
MCM-41 has a capillary system uniform pore size 4-5nm sized, hexagonal, one-way, to shape Nazi boss together to create a honeycomb structure, large surface area should tools and equipment in food preservation be applied tools and equipment in food preservation to the transition large size of molecules common in organic synthesis, tools and equipment in food preservation but the structural materials such as zeolites small capillary proved unsuitable.
So far, many studies on MCM-41 materials have been carried out, providing important information about the synthesis, structure and properties of space ... Especially the capillary system, the processing methods to obtain material properties of catalytic systems have properties suitable for certain reactions are attracting research interest of many scientists [6,7]. Some new materials to replace synthetic methods conformed tools and equipment in food preservation to the image of the Si atoms in the atom frame structure with Al, Ti, Fe, Ga ... constitutes the multifunctional catalytic systems, both for the catalytic properties tools and equipment in food preservation process caused by oxidation of the metal, has just had solid acid catalyst, tools and equipment in food preservation consistent with the process requires appropriate acidity.
A typical example of this type of catalyst is Ti-MCM-41 for the double bond of epoxy unsaturated compounds, or molecules Security ken natural compounds, such as α-pinene compounds. In materials Ti-MCM-41, Ti atoms replace copper in the form of Si position on the frame structure, creating materials that are lightweight oxidizing, acidic weak, consistent with the mild oxidizing create intermediate products are epoxy. So, here is the catalyst was prepared and applied to the oxidation process in real mellow.
With many different modulation methods such as decomposition-precipitation, sol gel method, co-precipitation method to exchange ... bring on the metal substrate with different tools and equipment in food preservation sizes. The researchers point out that, if the metal is dispersed more evenly with the smaller particle size, the higher the catalytic activity. Some like Pt/MCM-41 catalyst, effectively applied to the process of converting CO x, NO x, bring very positive results.
The first field application M41S materials can think of is that the catalytic cracking of large molecules, bulky. Corma [2] compared the Al-MCM-41, amorphous aluminosilicate and USY zeolite (zeolite Y) as the catalytic cracking of n-hexane, the active tools and equipment in food preservation USY than 140 times Al-MCM-41. This can be explained because of the Bronsted acid centers in zeolites than Al-MCM-41. However, Al-MCM-41 had higher activity than the amorphous aluminosilicate and zeolite USY equivalent in the molecular tools and equipment in food preservation process of cracking tools and equipment in food preservation heavy oil segment. Selectivity of the Al-MCM-41 in the cracking of heavy segment earned tools and equipment in food preservation more than liquid fuel, gas and coke less than aluminoslilicat amorphous. With USY zeolite, the cracking obtained mainly diesel, gasoline and much less than the cup. Because it is easy to see that for large molecules, the catalyst Al-MCM-41 is more beneficial.
After cracking, catalyst must be regenerated and new catalysts have a limited interest. For process applications, thermal stability of the catalyst is very important. In the fluidized catalyst, a catalyst to regeneration to remove coke. This process is carried out at a temperature of about 800 C and water vapor present. Under these conditions Al-MCM-41 tools and equipment in food preservation is unstable. Reliability increases as the Al content decreased, but when that catalytic activity also decreased.
A similar tools and equipment in food preservation trend for Al-MCM-48. Thus, hydrothermal durability of Al-MCM-41 and Al-MCM-48 needs to be improved before it can be applied widely in the process such as catalytic cracking of vacuum oil segment. There are several methods that can be used to improve tools and equipment in food preservation the thermal stability of the catalyst, which is one way to increase the thickness of the porous material, another way is to put the crystal into the hole (a hole or try to form amorphous to crystalline), tools and equipment in food preservation can thereby increasing the durability of porous material tools and equipment in food preservation to the equivalent of zeolite. However, the process