The Role Catalysts In Chemical Reactions, Their Importance In Industry

The Role Catalysts In Chemical Reactions, Their impressiveness In Industry, Problemsand New DevelopmentsOXFORD AND CAMBRIDGE SCHOOLS EXAMINATION BOARD. General Certificate Examination- right Level Chemistry (Salters) - Paper 3 mock.ROBERT TAYLOR U6JW.A Catalyst is a substance that alters the rate of a reaction. The catalystremains unchanged at the end of the reaction. The process is called catalysis.In this report I aim pass to explain the role of catalysts in chemicalreactions and their importance in industry. I willing also outline the problemsassociated with the use of some catalysts and discuss, using bookexamples, stark naked developments in this atomic number 18a which will help reduce upon to theenvironment.The process of catalysis is essential to the modern day manufacturing industry.Ninety per cent, over a trillion dollars worth, of manufactured items areproduced with the help of catalysts every year. It is indeed logical thatscientists are constantly searching fo r new alter catalysts which willimprove efficiency or produce a greater yield.An acid-forming catalyst works due its acid nature. Catalysts are strongacids and readily give up hydrogen ions, or protons H+. Protons can be releasedfrom hydrated ions, for example H3O+, but more commonly they are released fromionis fit hydroxyl groups (R-OH) where the O-H bond is broken to produce R-O-and H+. When the reactant receives protons from an acid it beares aconformational change, (change in shape and configuration), and becomes areactive intermediate. The intermediate can then all become an isomer byreturning a proton to the catalyst, or it may undergo a further reaction andform a completely new molecule.Up until the mid - 1960s silica- aluminum oxide gels were used to catalyse the crack cocaineof hydrocarbons. This form of cracking is where the large molecules in oil areconverted into small, highly fickle molecules. However because the size of thepores of silica-alumina gels was so va riable, (ranging from 0.1nm to 50nm), andthe fact that their shape was so variable, they were hardly ideal catalysts. Dueto the large size of their cavities, large carbonaceous products were able toform in the cavities thus lowering the reactivity if the catalyst. Catalysiswith alumina silica-gels was also difficult to control precisely because oftheir indefinite structure, and thus abrasive d... ...ce onthe surface of the solid therefore the solvent only acts as a form of heattransfer and a working fluid.In summary I see Supported reagents as the trump thinkable solution to theproblems associated with catalysis due to their easy use and their ability to berecovered and re-used. They have a high take aim of activity and improvedselectivity in reactions. This is accompanied by their highly catalytic activitywhich leads to the best possible level of performance in commercial uses. Thishas already been turn up by the use of active reagents in Friedel - Craftsreactions. These re actions originally had the drawbacks of firstly thehydrolysed aluminium chloride containing aqueous effluent which is produced, andsecondly the by-products such as polymeric tars and di- and polysubstituted by-products which are produced which unless they can be successfully removed makethe product impure. By using a supported reagent catalyst, in most cases thedesired level of activity can be achieved but the catalyst can be removed easilyfrom the reaction mixture and re-used. I personally therefore feel that thefuture of environmentally friendly catalysis lies with supported reagentcatalysts.