Carbonnanotube(CNT)-supportedRunanoparticleswithmeansizesrangingfrom2.3to9.2nmwerepreparedbydifferentpost-treatmentsandstudiedforFischer-Tropsch(FT)synthesis.TheeffectsofRuparticlesizeoncatalyticbehaviorswereinvestigatedatbothshorterandlongercontacttimes.Atshortercontacttime,wherethesecondaryreactionswereinsignificant,theturnoverfrequency(TOF)forCOconversionwasdependentonthemeansizeofRuparticles;TOFincreasedwiththemeansizeofRuparticlesfrom2.3to6.3nmandthendecreasedslightly.Atthesametime,theselectivitiestoC5+hydrocarbonsincreasedgraduallywiththemeansizeofRuparticlesupto6.3nmandthenkeptalmostunchangedwithafurtherincreaseinRuparticlesize.Atlongercontacttime,C10-C20selectivityincreasedsignificantlyattheexpenseofC21+selectivity,suggestingtheoccurrenceoftheselectivehydrocrackingofC21+toC10-C20hydrocarbons.
