Single-catalyst particle spectroscopy of alcohol-to-olefins conversions: Comparison between SAPO-34 and SSZ-13

Qingyun Qian; Javier Ruiz-Martinez; Mohamed Mokhtar; Abdullah M. Asiri; Shaeel A. Al-Thabaiti; Suliman N. Basahel; Bert M. Weckhuysen

doi:10.1016/j.cattod.2013.09.056

Single-catalyst particle spectroscopy of alcohol-to-olefins conversions: Comparison between SAPO-34 and SSZ-13

Qingyun Qian
, Javier Ruiz-Martinez^*
, Mohamed Mokhtar
, Abdullah M. Asiri
, Shaeel A. Al-Thabaiti
, Suliman N. Basahel
, Bert M. Weckhuysen

^*Corresponding author for this work

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

The formation of distinct hydrocarbon pool (HCP) species on individual micron-sized SAPO-34 and SSZ-13 crystals have been compared during methanol-to-olefins (MTO) and ethanol-to-olefins (ETO) conversion processes. In situ UV-vis micro-spectroscopy reveals the formation of 400 nm and 580 nm absorption bands, which are ascribed to poly-alkylated benzene (PAB) carbocations, the most active HCP species and poly aromatics (PA) the deactivating species, respectively. PAB formation within both catalysts is fitted with first-order kinetics at low reaction temperatures and activation energies (Ea) can be calculated, while PA/PAB ratio is calculated to monitor the deactivation process for different reaction temperatures. The results show that for both activation and deactivation processes, methylation reactions are leading in MTO and are controlled by acid strength; while olefins condensation reactions are governing in ETO and are affected more by acid site density. Moreover, the distribution of HCP species is visualized by confocal fluorescence microscopy, which demonstrates that the acid site density plays an important role on the local catalytic performance. Finally, synchrotron-based IR micro-spectroscopy reveals different activity of the two catalysts as shown by the intensity and frequency of distinct characteristic bands. (C) 2013 Elsevier B.V. All rights reserved.

Original language	English
Pages (from-to)	14-24
Number of pages	11
Journal	Catalysis Today
Volume	226
DOIs	https://doi.org/10.1016/j.cattod.2013.09.056
Publication status	Published - 1 May 2014

Funding

This research work is funded by the Netherlands Research School Combination-Catalysis (NRSC-C) and the Deanship of Scientific Research (DSR) of King Abdulaziz University, Jeddah under grant number (T-002-431). The authors gratefully acknowledge DSR for technical and financial support. We also acknowledge SOLEIL for access to the synchrotron radiation facilities under proposal number 20120471 and we would like to thank Dr. Frederic Jamme and Dr. Paul Dumas for their kind help and discussions. Dr. Jan Kornatowski (Max Planck Institute, Mulheim, Germany) and Dr. Einar A. Eilertsen (University of Oslo, Norway) are acknowledged for providing the SAPO-34 and SSZ-13 crystals, respectively. Javier Ruiz-Martinez (Utrecht University, the Netherlands) also acknowledges CW-NWO for his VENI grant.

Keywords

Alcohol-to-olefins
Micro-spectroscopy
Acid strength
Acid site density
Coke formation
Chabazite
ZEOLITE H-BETA
IN-SITU FTIR
REACTION-MECHANISM
UV/VIS MICROSPECTROSCOPY
HYDROCARBON FORMATION
REACTION CENTERS
COKE FORMATION
MTO REACTION
METHANOL
DEACTIVATION

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10.1016/j.cattod.2013.09.056

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@article{727f2b35070645c48704c81331497b9f,

title = "Single-catalyst particle spectroscopy of alcohol-to-olefins conversions: Comparison between SAPO-34 and SSZ-13",

abstract = "The formation of distinct hydrocarbon pool (HCP) species on individual micron-sized SAPO-34 and SSZ-13 crystals have been compared during methanol-to-olefins (MTO) and ethanol-to-olefins (ETO) conversion processes. In situ UV-vis micro-spectroscopy reveals the formation of 400 nm and 580 nm absorption bands, which are ascribed to poly-alkylated benzene (PAB) carbocations, the most active HCP species and poly aromatics (PA) the deactivating species, respectively. PAB formation within both catalysts is fitted with first-order kinetics at low reaction temperatures and activation energies (Ea) can be calculated, while PA/PAB ratio is calculated to monitor the deactivation process for different reaction temperatures. The results show that for both activation and deactivation processes, methylation reactions are leading in MTO and are controlled by acid strength; while olefins condensation reactions are governing in ETO and are affected more by acid site density. Moreover, the distribution of HCP species is visualized by confocal fluorescence microscopy, which demonstrates that the acid site density plays an important role on the local catalytic performance. Finally, synchrotron-based IR micro-spectroscopy reveals different activity of the two catalysts as shown by the intensity and frequency of distinct characteristic bands. (C) 2013 Elsevier B.V. All rights reserved.",

keywords = "Alcohol-to-olefins, Micro-spectroscopy, Acid strength, Acid site density, Coke formation, Chabazite, ZEOLITE H-BETA, IN-SITU FTIR, REACTION-MECHANISM, UV/VIS MICROSPECTROSCOPY, HYDROCARBON FORMATION, REACTION CENTERS, COKE FORMATION, MTO REACTION, METHANOL, DEACTIVATION",

author = "Qingyun Qian and Javier Ruiz-Martinez and Mohamed Mokhtar and Asiri, \{Abdullah M.\} and Al-Thabaiti, \{Shaeel A.\} and Basahel, \{Suliman N.\} and Weckhuysen, \{Bert M.\}",

year = "2014",

month = may,

day = "1",

doi = "10.1016/j.cattod.2013.09.056",

language = "English",

volume = "226",

pages = "14--24",

journal = "Catalysis Today",

issn = "0920-5861",

publisher = "Elsevier BV",

}

TY - JOUR

T1 - Single-catalyst particle spectroscopy of alcohol-to-olefins conversions

T2 - Comparison between SAPO-34 and SSZ-13

AU - Qian, Qingyun

AU - Ruiz-Martinez, Javier

AU - Mokhtar, Mohamed

AU - Asiri, Abdullah M.

AU - Al-Thabaiti, Shaeel A.

AU - Basahel, Suliman N.

AU - Weckhuysen, Bert M.

PY - 2014/5/1

Y1 - 2014/5/1

N2 - The formation of distinct hydrocarbon pool (HCP) species on individual micron-sized SAPO-34 and SSZ-13 crystals have been compared during methanol-to-olefins (MTO) and ethanol-to-olefins (ETO) conversion processes. In situ UV-vis micro-spectroscopy reveals the formation of 400 nm and 580 nm absorption bands, which are ascribed to poly-alkylated benzene (PAB) carbocations, the most active HCP species and poly aromatics (PA) the deactivating species, respectively. PAB formation within both catalysts is fitted with first-order kinetics at low reaction temperatures and activation energies (Ea) can be calculated, while PA/PAB ratio is calculated to monitor the deactivation process for different reaction temperatures. The results show that for both activation and deactivation processes, methylation reactions are leading in MTO and are controlled by acid strength; while olefins condensation reactions are governing in ETO and are affected more by acid site density. Moreover, the distribution of HCP species is visualized by confocal fluorescence microscopy, which demonstrates that the acid site density plays an important role on the local catalytic performance. Finally, synchrotron-based IR micro-spectroscopy reveals different activity of the two catalysts as shown by the intensity and frequency of distinct characteristic bands. (C) 2013 Elsevier B.V. All rights reserved.

AB - The formation of distinct hydrocarbon pool (HCP) species on individual micron-sized SAPO-34 and SSZ-13 crystals have been compared during methanol-to-olefins (MTO) and ethanol-to-olefins (ETO) conversion processes. In situ UV-vis micro-spectroscopy reveals the formation of 400 nm and 580 nm absorption bands, which are ascribed to poly-alkylated benzene (PAB) carbocations, the most active HCP species and poly aromatics (PA) the deactivating species, respectively. PAB formation within both catalysts is fitted with first-order kinetics at low reaction temperatures and activation energies (Ea) can be calculated, while PA/PAB ratio is calculated to monitor the deactivation process for different reaction temperatures. The results show that for both activation and deactivation processes, methylation reactions are leading in MTO and are controlled by acid strength; while olefins condensation reactions are governing in ETO and are affected more by acid site density. Moreover, the distribution of HCP species is visualized by confocal fluorescence microscopy, which demonstrates that the acid site density plays an important role on the local catalytic performance. Finally, synchrotron-based IR micro-spectroscopy reveals different activity of the two catalysts as shown by the intensity and frequency of distinct characteristic bands. (C) 2013 Elsevier B.V. All rights reserved.

KW - Alcohol-to-olefins

KW - Micro-spectroscopy

KW - Acid strength

KW - Acid site density

KW - Coke formation

KW - Chabazite

KW - ZEOLITE H-BETA

KW - IN-SITU FTIR

KW - REACTION-MECHANISM

KW - UV/VIS MICROSPECTROSCOPY

KW - HYDROCARBON FORMATION

KW - REACTION CENTERS

KW - COKE FORMATION

KW - MTO REACTION

KW - METHANOL

KW - DEACTIVATION

U2 - 10.1016/j.cattod.2013.09.056

DO - 10.1016/j.cattod.2013.09.056

M3 - Article

SN - 0920-5861

VL - 226

SP - 14

EP - 24

JO - Catalysis Today

JF - Catalysis Today

ER -

Single-catalyst particle spectroscopy of alcohol-to-olefins conversions: Comparison between SAPO-34 and SSZ-13

Abstract

Funding

Keywords

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