Recent research advances on catalysts for selective hydrogenation of ethyne

Guo, Jiawen; Lei, Yiming; Liu, Huimin; Li, Yuqiao; Li, Dezheng; He, Dehua

doi:10.1039/d3cy00615h

Cited by 8 publications

(8 citation statements)

References 146 publications

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“…3−5 The acetylene impurity poisons the catalyst by reducing its activity and life span and also affects the quality of the polythene product. 6 Hence, to obtain polymer-grade ethylene, acetylene concentration must be kept below 5 ppm. 7−9 Out of all the approaches available for acetylene removal from ethylene feed, selective hydrogenation of acetylene has gained significant interest among researchers because of its simplicity� the process being environment friendly and requiring low consumption of energy.…”

Section: Introductionmentioning

confidence: 99%

“…Out of all the approaches available for acetylene removal from ethylene feed, selective hydrogenation of acetylene has gained significant interest among researchers because of its simplicitythe process being environment friendly and requiring low consumption of energy. , An ideal catalyst for this purpose is one that selectively hydrogenates acetylene to ethylene without further hydrogenating it to ethane . Semihydrogenation (S–H) of acetylene involves hydrogenation of C 2 H 2 to C 2 H 4 via a C 2 H 3 intermediate where molecular hydrogen is used as the source of H atoms.…”

Section: Introductionmentioning

confidence: 99%

“…Under this circumstance, the ethylene molecule prefers to bind via the ethylidyne mode (involving the Pd-trimer) and di-σ mode (involving the Pd-dimer), which possess a high adsorption energy. This is detrimental to ethylene selectivity because hydrogenation of ethylene to ethane is now preferred over ethylene desorption. , One way to overcome this drawback is by decreasing the size of the Pd ensemble. This can be achieved in several ways: (a) selectively covering the active sites with CO or sulfur, , (b) dispersing Pd atoms onto supports like nanodiamond graphene, N-graphene, and MgO, and (c) producing alloys or intermetallic compounds that involve the introduction of a second metal like Ag, , Cu, , Au, In, Ga, , Zn, and Pb .…”

Section: Introductionmentioning

confidence: 99%

“…10,11 An ideal catalyst for this purpose is one that selectively hydrogenates acetylene to ethylene without further hydrogenating it to ethane. 6 Pd-based catalysts have been extensively studied for S−H of acetylene. 12,13 However, overhydrogenation of acetylene to ethane and the production of 1−3 butadiene as green oil precursors 14,15 are a serious concern while using them to catalyze the reaction.…”

Section: Introductionmentioning

confidence: 99%

“…Ethylene, an important building block in the petrochemical industry, is primarily produced by steam cracking of naphtha and natural gas. , Besides being used as a feedstock for the production of chemicals such as ethylene oxide, ethylene glycol, and ethylene dichloride, ethylene serves as a monomer for the synthesis of polyethylene. However, the catalyst catalyzing the ethylene polymerization reaction (i.e., the Ziegler–Natta catalyst) is sensitive to the presence of acetylene impurities in ethylene feeds. − The acetylene impurity poisons the catalyst by reducing its activity and life span and also affects the quality of the polythene product . Hence, to obtain polymer-grade ethylene, acetylene concentration must be kept below 5 ppm. − …”

Section: Introductionmentioning

confidence: 99%

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Unraveling the Role of Single-Atom Catalysts Immobilized onto Metal–Organic Frameworks in Selective Acetylene Hydrogenation: An Implementation of the Active Site Isolation Strategy

Ganai,

Sarkar

2024

J. Phys. Chem. C

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The active site isolation strategy has long been used to perform selective hydrogenation of acetylene. Out of all of the approaches available for isolating active sites, the use of single-atom catalysts (SACs) provides an attractive route to enhancing selectivity. Herein, SACs in the form of metal alkoxides (where the metal varies from Sc to Zn) have been immobilized onto the organic linkers of the UiO-67 metal−organic framework (MOF), and density functional theory (DFT) calculations have been used to thoroughly examine their hydrogenation ability. Given that there are four pathways detrimental to C 2 H 4 selectivity, namely, (a) C 2 H 4 hydrogenation pathway, (b) C 2 H 2 overhydrogenation pathway, (c) CHCH 3 hydrogenation pathway, and (d) C 2 oligomerization to 1,3-butadiene, UiO-67(Co) has been screened out to be the most efficient catalyst. Comparison with other studies shows that the hydrogenation ability of the UiO-67(Co) MOF is superior to that of many Pd-based catalysts and some non-Pd-based catalysts. Although isolation of active sites has been shown to effectively inhibit the production of green oils, our findings are contrary to the previously reported phenomena. Our study shows that the use of SACs does not guarantee inhibition of green oil formation�two C 2 molecules can adsorb at the same active site and can undergo C−C coupling. Selectivity of the reaction is hampered when C 2 oligomerization to 1,3-butadiene becomes more competent than the C 2 H 4 desorption pathway. In the realm of SACs, the choice of modulating the ethylene adsorption mode/energy is not available, and hence, we have reported a new strategy to enhance C 2 H 4 selectivity. Since the availability of H atoms is crucial for the hydrogenation process, the key to attaining selectivity is to reduce the availability of H atoms to an extent that ethylene hydrogenation can be prevented without hampering acetylene hydrogenation to ethylene. This criterion is accurately met by UiO-67(Co).

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Unraveling the Role of Single-Atom Catalysts Immobilized onto Metal–Organic Frameworks in Selective Acetylene Hydrogenation: An Implementation of the Active Site Isolation Strategy

Ganai,

Sarkar

2024

J. Phys. Chem. C

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Acetylene Hydrogenation Processes Studied Using CFD in a Packed Bed Reactor

Guo,

Xin,

Du Du

et al. 2024

Chem Eng & Technol

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Acetylene hydrogenation reactions (AHR) are typically carried out in fixed bed reactors (FBRs) with high diameter‐to‐particle diameter (D/d). In this study, first, a real catalyst bed was built using the discrete element method, and the suitability of the bed was assessed using empirical equations. Second, a discrete element method‐computational fluid dynamics (DEM‐CFD) model was developed using CFD in conjunction with the reaction mechanism to simulate the AHR in the FBR and was compared with the experimental results. The results show that the DEM‐CFD can well predict the 3D interactions of velocity, temperature, and species for different D/d. The results can provide favorable theoretical guidance for the optimization of FBR and process intensification.

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