What is Catal­y­sis or Cat­a­lysts, So what?

This short mes­sage is intended to pro­vide ways to explain what catal­y­sis is. Count­less times, I’ve been asked about what is catal­y­sis from per­sons of dif­fer­ing back­grounds: immi­gra­tion offi­cials, four­somes on a golf course, exec­u­tives in air­planes, or neigh­bors. To those of us who work in the field, we see tremen­dous value which has repeat­edly been sup­ported by sur­veys of the impact of catal­y­sis upon finan­cial mea­sur­ing tools, like the GNP (Gross National Prod­uct), but we need to be able to explain our pro­fes­sion to those not famil­iar with the technology.

Catal­y­sis is a tech­nol­ogy which increases the rate of a chem­i­cal reac­tion. This tech­ni­cal field employs both sci­en­tists and engi­neers. Cat­a­lysts are the mate­ri­als used by these per­sons to explore the phe­nom­e­non of catal­y­sis. Cat­a­lysts are mate­ri­als which speed up chem­i­cal reac­tions with­out the cat­a­lyst being con­sumed; they are mate­ri­als which induce change. More specif­i­cally, cat­a­lysts are mate­ri­als which change the rate of attain­ment of chem­i­cal equi­lib­rium with­out them­selves being changed or con­sumed in the process. Cat­a­lysts also pro­vide selec­tiv­ity or speci­ficity to par­tic­u­lar prod­ucts which are more desir­able than oth­ers. All these attrib­utes about catal­y­sis and cat­a­lysts trans­late to energy sav­ings, less pol­lu­tion, fewer side prod­ucts, lower cost reac­tor mate­ri­als, and ulti­mately prod­ucts which reduce global warm­ing. It has been said (A. Mit­tasch) that “chem­istry with­out catal­y­sis would be a sword with­out a handle…or a bell with­out sound.”

Catal­y­sis is the key to both life and lifestyle. It is an essen­tial tech­nol­ogy for chem­i­cal and mate­ri­als man­u­fac­tur­ing, for fuel cells and other energy con­ver­sion sys­tems, for com­bus­tion devices, and for pol­lu­tion con­trol sys­tems which greatly impact every­one on our planet. Some other spe­cific exam­ples of what cat­a­lysts do include appli­ca­tions for:

  • Fuels & Energy — Over half the world’s gaso­line is cur­rently pro­duced by a process devel­oped in 1942 called Fluid Cat­alytic Crack­ing (FCC). This process rev­o­lu­tion­ized the petro­leum indus­try by more effi­ciently trans­form­ing higher boil­ing oils into lighter, usable prod­ucts. FCC pro­duces gaso­line as well as heat­ing oil, fuel oil, propane, butane, and chem­i­cal feed­stocks that are instru­men­tal in pro­duc­ing other prod­ucts such as plas­tics, syn­thetic rub­bers and fab­rics, and cos­met­ics. It is con­sid­ered one of the most impor­tant chem­i­cal engi­neer­ing achieve­ments of the 20th cen­tury. In the future, cat­a­lysts will be used to pro­duce clean energy from renew­able energy sources, such as hydro­gen for fuel cells and trans­porta­tion fuels from non-edible biomass.
  • Emis­sions — Auto­mo­bile emis­sion cat­a­lysts have been devel­oped since the 1960s to destroy CO, NOx and hydro­car­bon emis­sions from mobile vehi­cles. Cat­a­lysts are also used to destroy the ori­gins of sul­fur based emis­sions in the com­bus­tion of fuels. In addi­tion cat­a­lysts are widely used to destroy the objec­tion­able emis­sions from the world’s coal fired power plants.
  • Poly­mers — Cat­a­lysts are also used in the pro­duc­tion of the world’s poly­mers. Cur­rent exam­ples of poly­mers include adhe­sives, coat­ings, foams, and pack­ag­ing mate­ri­als, tex­tile and indus­trial fibers, com­pos­ites, elec­tronic devices, bio­med­ical devices, opti­cal devices, and pre­cur­sors for many newly devel­oped high-tech ceramics.
  • Life — Enzymes are one exam­ple of cat­a­lysts within our bod­ies which are crit­i­cal to main­tain­ing life. Fur­ther, the pos­si­bil­ity of ana­lyz­ing and ulti­mately manip­u­lat­ing genes rests on the cat­alytic prop­er­ties of RNA to repli­cate mol­e­cules con­tain­ing bio­log­i­cal information.
  • Health — The phar­ma­ceu­ti­cal indus­try employ­ees large amounts of cat­a­lysts needed to pro­duce the speci­ficity of prod­ucts they require. Cat­a­lysts used in the pro­duc­tion of drugs are used to save lives and improve the health and lifestyle of peo­ple around the world.
  • Food — Cat­a­lysts are widely used in food pro­cess­ing and enhance the per­for­mance of other con­sumer prod­ucts such as laun­dry detergents.

The eco­nomic con­tri­bu­tion from catal­y­sis is as remark­able as the phe­nom­e­non itself. Four sec­tors of the world’s econ­omy are petro­leum, energy pro­duc­tion, chem­i­cals pro­duc­tion, and the food indus­try; together they account for more than 10 tril­lion dol­lars of the world’s GNP, and all of these are crit­i­cally depen­dent on the use of cat­a­lysts. Esti­mates are that catal­y­sis con­tributes to greater than 35% of global GDP; the biggest part of this con­tri­bu­tion comes from the gen­er­a­tion of high energy fuels (i.e., gaso­line, diesel, hydro­gen) which depend crit­i­cally on the use of small amounts of cat­a­lysts in our world’s petro­leum refiner­ies. As a busi­ness, the cat­a­lyst mar­ket itself is grow­ing from the cur­rent US$12 bil­lion, so that catal­y­sis costs are much less than 0.1% of the sales rev­enue from the prod­ucts which they create.

The North Amer­i­can Catal­y­sis Soci­ety is a not-for-profit pro­fes­sional orga­ni­za­tion of over 1,500 sci­en­tists and engi­neers who work in the field of catal­y­sis. The web­site for the Soci­ety, www.nacatsoc.org pro­vides infor­ma­tion to mem­bers and to the pub­lic about pro­fes­sional activ­i­ties as well as fold­ers con­tain­ing infor­ma­tion on catal­y­sis sci­ence. Those seek­ing addi­tional infor­ma­tion and other detailed exam­ples on what catal­y­sis is, does, or the value it pro­vides are encour­age to look fur­ther at the edu­ca­tional sub­fold­ers on this web­site. Another resource is the excel­lent text­book: Fun­da­men­tals of Indus­trial Cat­alytic Processes, by C. H. Bartholomew and Robert J. Far­rauto, pub­lished by John Wiley & Sons; 2nd edi­tion (2005), ISBN-13: 978–0471457138
John Armor
GlobalCatalysis.com, Feb­ru­ary 2008
(with sug­ges­tions from Bob Far­rauto and Enrique Iglesia)