Using Water as a Co-catalyst in Heterogeneous Catalysis to Improve Activity and Selectivity

2018 Spring Symposium

Lars C. Grabow, Depart­ment of Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing, Uni­ver­si­ty of Hous­ton, Hous­ton, TX 77204–4004, USA

Abstract — “What hap­pens when you add water?” is pos­si­bly the most fre­quent­ly asked ques­tion after pre­sen­ta­tions in het­ero­ge­neous catal­y­sis. In this talk, I will demon­strate that this ques­tion is indeed para­mount and that the pres­ence of even minute amounts of water can dras­ti­cal­ly change reac­tion rates and prod­uct selec­tiv­i­ties. Exam­ples include water-medi­at­ed pro­ton hop­ping across a met­al-oxide sur­face, oxi­da­tion of car­bon monox­ide at the gold/titania inter­face, and hydrodeoxy­gena­tion of phe­no­lic com­pounds over tita­nia sup­port­ed ruthe­ni­um cat­a­lysts. Togeth­er, these exam­ples demon­strate that water can act as co-cat­a­lyst in a vari­ety of cat­alyt­ic reac­tions and by vary­ing the amount of water it may be pos­si­ble to tune reac­tion rates and prod­uct selec­tiv­i­ty.