Increase of light aromatics space time yield by addition of SAPO-34 into multifunctional catalyst

Sep 29, 2026

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Addition of SAPO-34 to a multifunctional catalyst system is used to improve syngas conversion toward light aromatics, specifically benzene, toluene and xylene (BTX). The study couples ZnCrOX methanol-synthesis components with a 6Mn4Zr/H-ZSM-5 or 6Mn4Zr/SAPO-34 framework and examines how SAPO-34 loading, Zn/Cr composition, and catalyst structure affect CO conversion and BTX selectivity. Optimized conditions reach high CO conversion and BTX space-time yield, and the catalyst remains relatively stable over extended reaction time.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Introduction

Oxide-zeolite (OX-ZEO) route and tandem mechanism

Constraints in light aromatics (STA) and proposed strategies

Experimental

Chemical and physical properties of catalysts

Synthesis of catalysts

RSC Advances PAPER Increase of light aromatics space time yield by addition of SAPO-34 into multifunctional catalyst Cite this: RSC Adv., 2026, 16, 353 Received 10th November 2025 Accepted 18th December 2025 DOI: 10.1039/d5ra08666c[rsc.li/rsc-advances](rsc.li/rsc-advances) Shiyu Liu, Qiuyun Huang, Jie Wang, Weihua Shen* and Yunjin Fang* In this research, SAPO-34 were added into 6Mn4Zr/H-ZSM-5 catalyst and the tri-components catalyst was then granule mixed with ZnCrOX, which is regarded as methanol synthesis component. The introduction of SAPO-34 could facilitate the accumulation of HCPs and promote conversion of CO. As methanol & DME were preferentially consumed over HCPs in SAPO-34, the selectivity of light aromatics benzene, toluene and xylene (BTX) increased by inhibiting further methylation. The addition of ZnXCr could further remarkably enhance the conversion of CO because of it high activity in methanol & DME synthesis, and thus increase the space time yield of BTX components. The inﬂuence of ZnXCr composition, amount of SAPO-34 and 6Mn4Zr on catalyst performance were investigated. The reaction conditions were further optimized to achieve both high CO conversion (41 . 51%) and BTX selectivity (31 .37%) . The space-time yield of BTX could achieve 105 . 90 mg gcat−1 h−1 . The stability of optimized catalyst under optimal reaction condition were evaluated, after 100 h reaction, CO conversion could still reach 36.49% with BTX space time yield of 76 .36 mg gcat−1 h−1 . Introduction The conversion of syngas to value added chemicals has drawn both academic and industrial interests. A novel route named as oxide-zeolite (OX-ZEO) was proposed by Bao et al.,1,2 and achieved great success in selective conversion of syngas to ole􀀁n (C2–C4 ole􀀁ns, named as STO)1,2 or aromatics (STA) .3–5 Generally, the reaction mechanism of OX-ZEO strategy could be concluded as a tandem pathway. CO was 􀀁rstly converted into intermediates including methanol and dimethyl ester (DME) over oxides, and then the intermediates subsequently diﬀuse into zeolite for further conversion. The zeolites applied in OXZEO strategy for production of light ole􀀁n are usually SAPO- 34, AlPO-18, etc.; while when generating aromatics (STA), ZSM-5 could be applied.1–3,6–8 In STA, methanol and DME serve as the primary intermediates generated over oxide components, leading to relatively low selectivity toward light aromatics (e.g., benzene, toluene, and xylene, summarized as BTX) in the conventional OX-ZEO strategy.9–12 Such limitation arises from the methylation of light aromatics at the external acid sites of H-ZSM-5, which produces heavier products (e.g., trimethylbenzene and tetramethylbenzene) . To achieve higher selectivity of light aromatics, silanization of zeolite was applied to eliminate the external acid sites.13,14 Moreover, H-ZSM-5 with shorter length in State Key Laboratory of Chemical Engineering and Low-Carbon Technology, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. E-mail: [whshen@ecust.edu.cn](whshen@ecust.edu.cn); [yjfang@ecust.edu.cn](yjfang@ecust.edu.cn); Tel:+86-21-64252829 b axis could promote diﬀusion of light aromatics thus also prevent the methylation mentioned above.15 Except for modi􀀁 -cation of H-ZSM-5, introducing SAPO-34 into OX-ZEO strategy could also avoid the generation of higher aromatics, which would be bene􀀁tted from the preferential conversion of intermediates in SAPO-34 rather than H-ZSM-5 .16 Early studies on STA were constrained by low CO conversion.1,4,7,13,17 To improve conversion, the activation ability of H2 and CO should be strengthened. Addition of H2 activation species (e.g., ZnO or MoOX) could directly enhance the activation of H2, and further improve the generation of oxygen vacancy (OV),1,7 however, the selectivity of aromatics would decrease even at little addition amount. Besides, constructing single-atom dispersed Fe into ZnCr spinel co

FAQs

What role does SAPO-34 play in improving BTX production?

SAPO-34 addition facilitates the accumulation of hydrocarbon pool species (HCPs) and promotes CO conversion. It also helps increase BTX selectivity by preferentially consuming methanol and DME and inhibiting further methylation.

How does ZnCrOX affect CO conversion and aromatics selectivity?

ZnXCr (from ZnCrOX) can significantly enhance CO conversion due to its high activity in methanol and DME synthesis. This improvement supports higher BTX space-time yield while the overall selectivity behavior depends on catalyst composition.

What performance is achieved after reaction-condition optimization and how is stability evaluated?

Optimized conditions target both high CO conversion and high BTX selectivity, yielding a BTX space-time yield of 105.90 mg gcat−1 h−1. After 100 h under optimal conditions, CO conversion remains 36.49% and BTX space-time yield is 76.36 mg gcat−1 h−1.

Sep 29, 2026

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