Synthesis of sub-micrometric SAPO-34 by a morpholine assisted two-step hydrothermal route and its excellent MTO catalytic performance

2019 ◽  
Vol 48 (8) ◽  
pp. 2606-2616 ◽  
Author(s):  
Syed ul Hasnain Bakhtiar ◽  
Sher Ali ◽  
Xiaotong Wang ◽  
Fulong Yuan ◽  
Zhibin Li ◽  
...  
Keyword(s):  
Hydrothermal Treatment ◽  
Crystal Size ◽  
Cost Effective ◽  
Catalytic Performance ◽  
Hydrothermal Route ◽  
Light Olefin ◽  
Structure Directing Agent ◽  
Olefin Selectivity

SAPO-34 with a sub-micrometer crystal size was synthesized by a double hydrothermal treatment employing cost-effective morpholine as a structure directing agent, which presented an enhanced catalytic lifetime (nearly 3 times the conventional one) in the reaction of methanol to olefins with a higher light olefin selectivity (total selectivity of 97.1%).

scholarly journals Fischer–Tropsch Synthesis for Light Olefins from Syngas: A Review of Catalyst Development

Reactions ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 227-257
Author(s):  
Arash Yahyazadeh ◽  
Ajay K. Dalai ◽  
Wenping Ma ◽  
Lifeng Zhang
Keyword(s):  
Pore Size ◽  
Crystal Size ◽  
Tropsch Synthesis ◽  
Light Olefins ◽  
Face Centered Cubic ◽  
Fischer Tropsch ◽  
Light Olefin ◽  
Structure Transition ◽  
Fischer Tropsch Synthesis ◽  
Olefin Selectivity

Light olefins as one the most important building blocks in chemical industry can be produced via Fischer–Tropsch synthesis (FTS) from syngas. FT synthesis conducted at high temperature would lead to light paraffins, carbon dioxide, methane, and C5+ longer chain hydrocarbons. The present work focuses on providing a critical review on the light olefin production using Fischer–Tropsch synthesis. The effects of metals, promoters and supports as the most influential parameters on the catalytic performance of catalysts are discussed meticulously. Fe and Co as the main active metals in FT catalysts are investigated in terms of pore size, crystal size, and crystal phase for obtaining desirable light olefin selectivity. Larger pore size of Fe-based catalysts is suggested to increase olefin selectivity via suppressing 1-olefin readsorption and secondary reactions. Iron carbide as the most probable phase of Fe-based catalysts is proposed for light olefin generation via FTS. Smaller crystal size of Co active metal leads to higher olefin selectivity. Hexagonal close-packed (HCP) structure of Co has higher FTS activity than face-centered cubic (FCC) structure. Transition from Co to Co3C is mainly proposed for formation of light olefins over Co-based catalysts. Moreover, various catalysts’ deactivation routes are reviewed. Additionally, techno-economic assessment of FTS plants in terms of different costs including capital expenditure and minimum fuel selling price are presented based on the most recent literature. Finally, the potential for global environmental impacts associated with FTS plants including atmospheric and toxicological impacts is considered via lifecycle assessment (LCA).

A fast route for synthesizing nano-sized ZSM-5 aggregates

2014 ◽  
Vol 2 (48) ◽  
pp. 20667-20675 ◽  
Author(s):  
Feng Pan ◽  
Xuchen Lu ◽  
Qingshan Zhu ◽  
Zhimin Zhang ◽  
Yan Yan ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Coke Deposition ◽  
Hydrothermal Route ◽  
Fast Route ◽  
Olefin Selectivity ◽  
Excellent Catalytic Performance

Nano-sized ZSM-5 aggregates have been rapidly synthesized from leached metakaolin by solid-like state conversion. Compared with the conventional hydrothermal route, the nano-sized ZSM-5 aggregates obtained by this method showed more excellent catalytic performance, C2–C4 olefin selectivity and longer lifetime to endure coke deposition.

scholarly journals Enhancing the light olefin selectivity of an iron-based Fischer–Tropsch synthesis catalyst by modification with CTAB

RSC Advances ◽  
2018 ◽  
Vol 8 (56) ◽  
pp. 32073-32083 ◽  
Author(s):  
Chuanxue Zhu ◽  
Yingxin Liu ◽  
Chao Huo ◽  
Huazhang Liu
Keyword(s):  
Catalytic Performance ◽  
Tropsch Synthesis ◽  
Hexadecyltrimethylammonium Bromide ◽  
Fischer Tropsch ◽  
Light Olefin ◽  
Fischer Tropsch Synthesis ◽  
Iron Based ◽  
Olefin Selectivity

The effects of the surfactant hexadecyltrimethylammonium bromide (CTAB) on the catalytic performance of a manganese-promoted iron (FeMn) catalyst for the Fischer–Tropsch to olefin (FTO) reaction were investigated.

Positive Role of Synthesis Method and Hard Template on the Catalytic Performance of SAPO-34 in Methanol to Olefin Reaction.

2020 ◽  
Vol 23 ◽  
Author(s):  
Sajjad Rimaz ◽  
Reza Katal
Keyword(s):  
Particle Size ◽  
Synthesis Method ◽  
Catalytic Performance ◽  
Hard Template ◽  
Structure Directing Agent ◽  
Positive Role ◽  
Methanol To Olefin ◽  
Dg Method ◽  
Synthesis Procedure

: In the present study, SAPO-34 particles were synthesized using hydrothermal (HT) and dry gel (DG) conversion methods in the presence of diethyl amine (DEA) as an organic structure directing agent (SDA). Carbon nanotubes (CNT) were used as hard template in the synthesis procedure to introduce transport pores into the structures of the synthesized samples. The synthesized samples were characterized with different methods to reveal effects of synthesis method and using hard template on their structure and catalytic performance in methanol to olefin reaction (MTO). DG conversion method results in smaller particle size in comparison with hydrothermal method, resulting in enhancing catalytic performance. On the other side, using CNT in the synthesis procedure with DG method results in more reduction in particle size and formation of hierarchical structure which drastically improves catalytic performance.

scholarly journals Offretite Zeolite Single Crystals Synthesized by Amphiphile-Templating Approach

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2238
Author(s):  
Eng-Poh Ng ◽  
Nur Hidayahni Ahmad ◽  
Fitri Khoerunnisa ◽  
Svetlana Mintova ◽  
Tau Chuan Ling ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Cost Effective ◽  
Acid Sites ◽  
Biofuel Production ◽  
Structure Directing Agent ◽  
High Crystallinity ◽  
Organic Templates ◽  
Synthesis Approach ◽  
Conventional Counterpart ◽  
Dual Functions

Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of offretite, viz. as structure-directing agent and as mesoporogen. The resulting offretite crystals, with a Si/Al ratio of 4.1, possess more acid sites than the conventional offretite due to their high crystallinity and hierarchical structure. The synthesized offretite is also more reactive than its conventional counterpart in the acylation of 2-methylfuran for biofuel production under non-microwave instant heating condition, giving 83.5% conversion with 100% selectivity to the desired product 2-acetyl-5-methylfuran. Hence, this amphiphile synthesis approach offers another cost-effective and alternative route for crystallizing zeolite materials that require expensive organic templates.

scholarly journals Probing the surface reactivity of nanocrystals by the catalytic degradation of organic dyes: the effect of size, surface chemistry and composition

2017 ◽  
Vol 5 (23) ◽  
pp. 11917-11929 ◽  
Author(s):  
Jordi Piella ◽  
Florind Merkoçi ◽  
Aziz Genç ◽  
Jordi Arbiol ◽  
Neus G. Bastús ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Surface Coating ◽  
Crystal Size ◽  
Organic Dyes ◽  
Catalytic Performance ◽  
Surface Reactivity ◽  
Catalytic Degradation ◽  
Comprehensive Study

We herein present a comprehensive study on how the catalytic performance and reusability of Au nanocrystals (NCs) are affected by systematic variations of crystal size, surface coating and composition.

Hydrothermal synthesis of Sn-Beta zeolites in F−-free medium

2018 ◽  
Vol 5 (11) ◽  
pp. 2763-2771 ◽  
Author(s):  
Hao Xu ◽  
Xudong Wang ◽  
Peng Ji ◽  
Haihong Wu ◽  
Yejun Guan ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Lewis Acid ◽  
Crystal Size ◽  
Acid Catalysts ◽  
Free Medium ◽  
Lewis Acid Catalysts ◽  
Structure Directing Agent ◽  
Highly Active ◽  
Beta Zeolites

Sn-Beta zeolites, with high Sn content and smaller crystal size, hydrothermally synthesized in F−-free medium using N-cyclohexyl-N,N-dimethylcyclohexanaminium hydroxide as the structure-directing agent with the assistance of Na+ and seed, are highly active as Lewis acid catalysts.

Composite HZSM-5 with Nanosheets for Higher Light Olefin Selectivity and Longer Lifetime in Catalytic Cracking Mixed Light Hydrocarbons

2015 ◽  
Vol 44 (12) ◽  
pp. 1697-1699 ◽  
Author(s):  
Subing Fan ◽  
Jiao Zhou ◽  
Junmin Lv ◽  
Min Liu ◽  
Hantao Huang ◽  
...  
Keyword(s):  
Catalytic Cracking ◽  
Light Hydrocarbons ◽  
Light Olefin ◽  
Olefin Selectivity

CTAB-assisted size controlled synthesis of SAPO-34 and its contribution toward MTO performance

2018 ◽  
Vol 47 (29) ◽  
pp. 9861-9870 ◽  
Author(s):  
Syed ul Hasnain Bakhtiar ◽  
Xiaotong Wang ◽  
Sher Ali ◽  
Fulong Yuan ◽  
Zhibin Li ◽  
...  
Keyword(s):  
Controlled Synthesis ◽  
Pore System ◽  
Light Olefin ◽  
Diffusion Limitations ◽  
Small Pore ◽  
Methanol To Olefin ◽  
Olefin Selectivity ◽  
Size Controlled

SAPO-34 shows higher light olefin selectivity in the reaction of methanol to olefin (MTO), but its small pore system implies diffusion limitations to bigger molecular products and results in coking too.

scholarly journals A Zirconium Metal-Organic Framework with SOC Topological Net for Catalytic Peptide Bond Hydrolysis

2021 ◽  
Author(s):  
Sujing Wang ◽  
Antoine Tissot ◽  
Guillaume Maurin ◽  
Tatjana Parac-Vogt ◽  
Christian Serre ◽  
...  
Keyword(s):  
Active Sites ◽  
Metal Organic Framework ◽  
Cost Effective ◽  
Peptide Bond ◽  
Catalytic Performance ◽  
Wide Range ◽  
Horse Heart Myoglobin ◽  
Metal Organic ◽  
Effective Synthesis ◽  
Organic Framework

<div>The discovery of nanozymes for selective cleavage of proteins would boost the emerging areas of modern proteomics, however, the development of efficient and reusable artificial catalysts for peptide bond hydrolysis is challenging. Here we report the detailed catalytic properties of a microporous zirconium carboxylate metal-organic framework, MIP-201, in promoting peptide bond hydrolysis in a simple dipeptide, as well as in horse-heart myoglobin (Mb) protein that consists of 153 amino acids. We demonstrate that MIP-201 features an excellent catalytic activity and selectivity, a good tolerance toward reaction conditions covering a wide range of different pH values, and importantly, an exceptional recycling ability associated with easy regeneration process. Taking into account the excellent catalytic performance of MIP-201 and its other advantages such as 6-connected Zr6 cluster active sites, the green, scalable and cost-effective synthesis, and an outstanding chemical and architectural stability, our finding suggests that MIP-201 may be a promising and practical alternative to the current commercially available catalysts for peptide bond hydrolysis.</div>

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