Triphenylmethane (Ph3CH) reacts with SZO300 to form [Ph3C][SZO300], Figure . Monitoring this reaction by 1 H NMR NMR spectroscopy shows small amounts of benzene and diphenylmethane also form (Figure ). Signals for Ph3C + , which would be evidence for leaching from the support, were not detected in these experiments. The diffuse reflectance UV-vis (DRUV) spectrum of [Ph3C][SZO300] shown in Figure . This spectrum contains a signal at 211 ppm, consistent with the formation of a supported trityl cation. Also present in this spectrum are signals for adsorbed Ph3 13 CH at 57 ppm and adsorbed Ph2 13 CH2 at 41 ppm. The minor signal at 49 ppm is an unknown impurity. The 13 C{ 1 H} MAS NMR spectrum of [Ph3C][SZO300] acquired with sufficiently long recycle delay to obtain quantitative information out the ratio of these peaks is also shown in Figure . From these data, the ratio of Ph3 13 C + : Ph3 13 CH : Ph2 13 CH2 is ~4:1:1. The elemental analysis of [Ph3C][SZO300] gives 1.16 % C. Using the relative surface coverages from C{ 1 H} MAS NMR data, there are ~0.04 mmol g -1 Ph3C + , or ~0.3 Ph3C + nm -2 , in this material. This value serves as a rough approximation for pyrosulfate loading in SZO300, assuming Ph3CH reacts with all accessible pyrosulfate. Using Ph3 13 CH-d15, where only the phenyl groups are deuterated, forms [Ph3C-d15][SZO300]. The 1 H MAS NMR spectrum contains a signal at 4.1 ppm (Figure ), which is tentatively assigned to the S-H that forms after hydride abstraction by transiently formed SO3.