Supporting Information: Tracing catalytic conversion. on single zeolite crystals in 3D. with nonlinear spectromicroscopy

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1 Supporting Information: Tracing catalytic conversion on single zeolite crystals in 3D with nonlinear spectromicroscopy Katrin F. Domke,, T. Alexander Riemer, Gianluca Rago, Andrei N. Parvulescu, Pieter C.A. Bruijnincx, Annika Enejder, Bert M. Weckhuysen, and Mischa Bonn, FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam, Utrecht University, Inorganic Chemistry and Catalysis Group, Universiteitsweg 99, NL-3584 CG Utrecht, and Chalmers University of Technology, Department of Chemical and Biological Engineering, SE Göteborg To whom correspondence should be addressed FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam Utrecht University, Inorganic Chemistry and Catalysis Group, Universiteitsweg 99, NL-3584 CG Utrecht Chalmers University of Technology, Department of Chemical and Biological Engineering, SE Göteborg Max Planck Institute for Polymer Research, Ackermannweg 10, D Mainz 1

2 Synthesis of H-beta zeolites For synthesis of H-beta crystals, 2.40 g of silica (Sipernat 50, Evonik Degussa), g of Al() 3 (0.079) (> 63.5 % Al 2 O 3, Acros), and g of NH 4 F(> 98 %, Sigma-Aldrich) were added into 7.57 g of a tetraethylammonium hydroxide solution (TEA, 35 wt %, Sigma-Aldrich), which resulted in a gel with a molar composition of 1.0SiO 2 :0.0125Al 2 O 3 :0.225TEA:0.4NH 4 F: 7.14H 2 O. The mixture was stirred at room temperature for 1 h and then transferred into a Teflon-lined steel autoclave with a full capacity volume of 50 ml (inner diameter of the Teflon bottle of 34 mm and height of 55 mm). The autoclave was placed in a preheated oven at 170 C for 7 days and afterwards quenched with tap water. The precipitated product was washed with three batches of hot water (70-80 C). The microcrystalline product was obtained by filtration, dried at 60 C overnight and calcined before testing. Derivation of the apparent adsorption enthalpy of 1-octene on H-beta, H 0 app For the adsorption reaction [alkene] + [BAS] [cation], where [s] is the concentration of species s, we define the equilibrium constant, K, as K =[cation]/[alkene][bas]. With [BAS] = 1 for the zeolite solid acid with an excess of acidic sites, K reduces to [cation]/[alkene]. As the band intensities of the retrieved CARS responses are directly proportional to the number of scatterers and the predominant conversion is from alkene to cation, the concentrations can be expressed as [cation] =I re f I and as [alkene] =I, where I re f are the band intensities of the pure liquid and I of the remaining inactivated C=C double bonds normalized to the band at cm 1 at varying temperature. Thus K can be expressed in terms of a band intensity ratio as K =(I re f I)/I. According to the Van t Hoff equation, lnk = H 0 app/rt + S/R, the slope of the plot lnk vs 1/T is H 0 app/r. As we do not know the behaviour outside the inspected temperature region, we refrain from estimating S. 2

3 Table overview band assignment Table 1: Overview of the CARS band positions and their assignment according to Raman shifts reported in literature. CARS shift (1/cm) Raman shift [a] (1/cm) assignment [a,b] O (=CH 2 as str) O (=CH 2 sym str) O (CH 3 as str) P (CH 3 as str) O (CH 2 sym str) P (CH 2 sym str) O (CH 2 as str) P (CH 3 sym str) O (CH 2 sym str) O (CH 2 sym str) O (C=C str) P (CH 2, CH 3 def) O (CH 3 asym def) O (CH 2 def) O (=CH 2 def) [a] 1-Octene band assignment following assignment for 1-butene by Durig and Compton. 1 [b] 1,2-propylene glycol following band assignment by Schönhals et al. 2 O: 1-octene; P: 1,2-propylene glycol 3

4 CARS and UV/vis responses of 2 µm large H-beta crystals a) /+16+-/17,2)89/18:,;+/1-5! C=C-H str C! -H str C=Cstr C=C-H bend /+16+-/17,2)89/18:,;+/1-5!"#$$!"$$$!%&$$!%'$$ ()*)+,-./01,2#34*5!"#$%!"$$%!"&$%!"'$% ()*)+,-./01,2"34*5 b) c) /+17+-/18,2)9:/19;,<+/1-6 /+17+-/18,2)9:/19;,<+/1-6 +!!"#$#!%&$#!%'$# ()*)+,-./01,2345*6!"#$#!%&$#!%'$# ()*)+,-./01,2345*6 Figure 1: CARS responses of 2 µm large H-beta crystals loaded with a) 1-octene, b) 1,2-propylene glycol, and c) a mixture of 1-octene and 1,2-propylene glycol in the temperature range between RT (black) and 140 C (light grey). Similar CARS experiments were also carried out with individual 2 µm sized H-beta particles (Si/Al = 20), approaching industrially relevant catalyst dimensions (Figure 1). Particles loaded with single reagents show the same characteristic vibrational fingerprints as described in the main text in detail for 100 C-samples of the larger crystals. The immediate onset of activation of 1- octene can be explained by the high Al content in the small crystals where aluminium zoning is 4

5 0.30 Absorbance wavelength (nm) 0.04 Absorbance wavelength (nm) Figure 2: The UV/vis spectra of 2 µm large H-beta crystals loaded with 1-octene (top) and the 1,2-propylene glycol/1-octene mixture (bottom) show three pronounced absorption bands at ca. 310, 375 and 460 nm that originate from the formation of polyenyl cations from 1-octene. 5

6 expected to be less pronounced as the particles are in fact of the dimension of the high-al content rim as observed in larger zeolite crystals. As evident from the spectra of the adsorbed reaction mixture, the glycol contribution clearly dominates the overall CARS response (Figure 1c). This different behaviour as compared to the larger crystals is ascribed to the facilitated adsorption of 1,2-propylene glycol versus 1-octene on the more hydrophilic smaller zeolites. Reconstructed 3D videos of 2PF spatial distribution of polyenyl side products at RT (2PF_RT.avi) and at 100 C (2PF_100.avi). References (1) Durig, J. R.; Compton, D. A. C. Journal of Physical Chemistry 1980, 84, (2) Schönhals, A.; Goering, H.; Brzezinka, K. W.; Schick, C. Journal of Physics: Condensed Matter 2003, 15, S1139 S