Fig. 1. An overview of the micro-spectroscopic toolbox utilized in this work to study aromatic spatiotemporal migration-agglomeration evolution and dynamic PAH-zeolite guest-host interplay at the single crystal level. Schematics of the zeolite crystal for infrared micro-spectroscopy imaging (b), structured illumination microscopy imaging (e, images were acquired by focusing on the middle z-plane of crystals to exclude external surface interference) and time-of-flight secondary ion mass spectrometry depth profiling (g). (a) The optical photograph of the capsule Z5@SiO2 (L) crystals. (c) Time-resolved 2D IR intensity maps of a Z5@SiO2 (L) crystal recorded in real time through custom-developed RQSI approach during methanol conversion at 475 °C for the 1615 cm-1 (aromatic species) vibrational bands. (d) 1D line-scan concentration plots of aromatic guests. (f) Supper-resolution spatiotemporal distribution of carbonaceous species obtained from SIM in Z5@SiO2 (L) crystals with time on stream (TOS). MTH reaction performance of Z5@SiO2 (L) at 475? °C and WHSV of 10 h-1 was presented in Fig. S9. The fluorescence intensities of the selected lines are also displayed. The SIM images are the fluorescence originating from the overlap of four curves with different laser excitations of 405?nm (detection at 435-485?nm, blue), 488?nm (detection at 500-545?nm, green), 561?nm (detection at 570-640?nm, yellow) and 640?nm (detection at 663-738?nm, magenta). (h) Nanoscale 3D reconstruction of 13C+ secondary ion depth profile of the Z5@SiO2 (L) crystal after 4 h of methanol conversion.

Fig. 2. (a) Schematic illustration of aromatic migration-agglomeration dynamics in molecular-scale zeolite confined space and spatiotemporal evolution within single crystal, taking methanol conversion over channel-structured ZSM-5 (3D MFI topology) as a prototypical system. (b) MTH reaction performance over Z5@SiO2 (20) at 475? °C and WHSV of 4 h-1. (c) Operando FTIR spectra for tracking the surface species evolution over Z5@SiO2 (L) crystals at 400 °C and detailed surface C1 species evolution routes with infrared signals attribution. (d) Time-evolving chromatograms of soluble coke extracted from the spent up-layer Z5@SiO2 (20) catalysts after HF digestion. See layered catalyst bed in Fig. S12. (e) Time-of-flight mass spectrogram after comprehensive two-dimensional gas chromatography of the soluble coke at 197 min of the reaction.

Fig. 3. The mass spectra of the liberated carbonaceous deposits obtained from the spent upper-layer Z5@SiO2 (20) catalysts by HF dissolution-CCl4 extraction after MTH reaction with WHSV of 4 h-1 at 475? °C for 5 min for illustrative purposes (a), at 475? °C for different durations (5-133 min) (b), at different temperatures (350-475? °C) and from the bottom-layer of H-ZSM-5 (105) with lower density of acidity (c).

Fig. 4. MALDI FT-ICR mass spectra of the extracts from the spent Z5@SiO2 (20) after 5?min reaction at 475? °C for comparing the feeding of 13C-methanol (a) and D-methanol (b) with normal methanol. (c) 13C MAS NMR spectroscopy of the isolated insoluble coke from Z5@SiO2 (20). (d) The identified conceivable PAH molecular structures and their channel-resolved spatial location in MFI pore network. (e) Full molecular picture of PAHs evolution routes and aromatic migration-agglomeration dynamic trajectory in molecular-scale zeolite confined space. PAH agglomerates evolve from long chain olefins and light polymethylbenzenes (“seeding”) to one-/two-ring PAHs behaving as building units for aromatic cluster formation (“growing”) and eventually to channel-passing aromatic agglomerates (“agglomerating”). Primary coking seeds mature from C4 to polymethylbenzenes and naphthalene in a dynamic manner. Direct atomic-resolution iDPC-STEM image of the coke-loaded short b-axis ZSM-5 crystals (~30 nm thickness) after MTH reaction at 475 °C with WHSV of 10 h-1 for 10 h from the (010) projection (f, left). Structural model of the MFI framework filled by channel-passing PAH molecules (f, right). Magnified iDPC-STEM images of an empty straight channel before reaction (h, top) and filled by a PAHs molecule after reaction (g, left). Corresponding structures of the MFI framework before (h, bottom) and after (g, right) the filling of channel-passing PAH molecules. The orange ellipses present the shapes of straight channels and the blue belts present the orientation of sinusoidal channels.

Fig. 5. MALDI FT-ICR mass spectra for extracts obtained from other channel-structured zeolites (ZSM-35@SiO2 and ZSM-22@SiO2) and the deduced possible molecular structure of PAHs. The indicated molecular structures are representative examples of possible structures. Lower signal-to-noise ratio observed in 1-D TON signifies a lower PAHs intensity.

Fig. 6. MALDI FT-ICR mass spectra for extracts obtained from other channel-structured zeolites (ZSM-35@SiO2 and ZSM-22@SiO2) and the deduced possible molecular structure of PAHs. The indicated molecular structures are representative examples of possible structures. Lower signal-to-noise ratio observed in 1-D TON signifies a lower PAHs intensity.