Anchoring Effect of Organosilanes on Hierarchical ZSM-5 Zeolite for Catalytic Fast Pyrolysis of Cellulose to Aromatics

Abstract

As an essential chemical feedstock, aromatics can be obtained from biomass by catalytic fast pyrolysis (CFP) technology, in which diffusion limitation is still a problem. In this study, several ZSM-5 zeolites with intercrystal stacking macropores were synthesized by adding organosilanes (OSAs) with different alkyl chain groups. Due to the structure-directing effect of the OSA, the prepared ZSM-5 zeolites possess a larger external surface area and pore volume than Blank-Z5. Moreover, the pore size is related to the extent of anchoring of the OSA and silicon–aluminum species in the zeolite precursor. Pyridine Fourier transform infrared (Py-FTIR) and NH 3 -temperature-programmed desorption (TPD) analyses show that the obtained ZSM-5 zeolites have a higher Brønsted acidity and total number of acid sites. In addition, excessive addition of OSA is not conducive to the growth of ZSM-5 zeolites. The catalytic performance of the synthesized ZSM-5 zeolites was evaluated by Py-GC/MS. The larger external surface area and pore volume improve the accessibility of the acid sites and thus promote the conversion of biomass into aromatics.

Strongly Electron-Interacting Ru–Ce Pair Sites in RuOx/CeO2–HAP for Efficient Oxidation of MMF to FDCA

“…As depicted in Figure a, the XRD patterns of CeO 2 –HAP and 2.5 wt % RuO x /CeO 2 –HAP displayed identical diffraction peaks, corresponding to HAP (JCPDS 09-0432) and CeO 2 (JCPDS 81-0792) . The average crystal size was calculated using the Scherrer equation (Table S1). For the undoped HAP, the crystal size was 15.5 nm.…”

“…The conversion of MMF and the yield of FDCA or intermediates were calculated by using the external standard calibration curve method based on the following equations 1a, the XRD patterns of CeO 2 −HAP and 2.5 wt % RuO x /CeO 2 −HAP displayed identical diffraction peaks, corresponding to HAP (JCPDS 09-0432) 43 and CeO 2 (JCPDS 81-0792). 44 The average crystal size was calculated using the Scherrer equation 45 (Table S1). For the undoped HAP, the crystal size was 15.5 nm.…”

Design and synthesis of core shells HZSM-5@MCM-41 with variable acidity and mesoporosity for lignin-catalyzed fast pyrolysis to prepare aromatics

“…2,[6][7][8] To solve the problem that conventional microporous zeolites are prone to carbon buildup and thus lead to catalyst deactivation, researchers have proposed various solutions. 9,10 Wang et al 9 synthesized a ZSM-5@S1 core-shell molecular sieve by design. The S1 shell of pure silicon acts as surface passivation, thereby reducing the production of carbon deposits.…”

“…The S1 shell of pure silicon acts as surface passivation, thereby reducing the production of carbon deposits. Zhou et al 10 synthesized ZSM-5 with inter crystal stacking macropores by adding organosilanes with different alkyl chain groups and applying it to the catalytic fast pyrolysis (CFP) of biomass. Their study showed that the larger surface area and pore volume improved the accessibility of acid sites, thus promoting the conversion of biomass to aromatics.…”