Conversion Of Phenylacetylene Research Articles

Rapidly solidified Al-Cu-Co quasicrystalline alloy: microstructure and catalytic properties

This study presents the characterisation and evaluation of the catalytic potential of an alloy with a composition referring to the quasicrystal from the Al-Cu-Co system. The material was synthesised through a melt-spinning process, providing rapid solidification conditions and a favourable material form of thin ribbons. Microstructural and chemical analyses were performed using scanning electron microscopy, X-ray diffraction and transmission electron microscopy methods. The obtained results confirmed the presence of a major phase which was a decagonal quasicrystal in the form of globular grains and additional crystalline phases occurring along the grain boundaries. The catalytic potential of the materials was explored using phenylacetylene hydrogenation. The catalyst, obtained by pulverising the ribbons, demonstrated catalytic activity with over 40% phenylacetylene conversion and selectivity exceeding 60% for styrene production under mild reaction conditions. The recovered catalyst displayed a stable phase composition, as confirmed by X-ray diffraction, and unchanged morphology, indicating the possibility of catalyst reuse for subsequent reaction cycles. The presented results provide insight into the experimental verification of the catalytic properties of the developed environmentally friendly catalysts.

Efficient Alkyne Semihydrogenation Catalysis Enabled by Synergistic Chemical and Thermal Modifications of a PdIn MOF.

Recently, there has been a growing interest in using MOF templating to synthesize heterogeneous catalysts based on metal nanoparticles on carbonaceous supports. Unlike the common approach of direct pyrolysis of PdIn-MOFs at high temperatures, this work proposes a reductive chemical treatment under mild conditions before pyrolysis (resulting in PdIn-QT). The resulting material (PdIn-QT) underwent comprehensive characterization via state-of-the-art aberration-corrected electron microscopy, N2 physisorption, X-ray absorption spectroscopy, Raman, X-ray photoelectron spectroscopy, and X-ray diffraction. These analyses have proven the existence of PdIn bimetallic nanoparticles supported on N-doped carbon. In situ DRIFT spectroscopy reveals the advantageous role of indium (In) in regulating Pd activity in alkyne semihydrogenation. Notably, incorporating a soft nucleation step before pyrolysis enhances surface area, porosity, and nitrogen content compared to direct MOF pyrolysis. The optimized material exhibits outstanding catalytic performance with 96% phenylacetylene conversion and 96% selectivity to phenylethylene in the fifth cycle under mild conditions (5 mmol phenylacetylene, 7 mg cat, 5 mL EtOH, R.T., 1 H2 bar).

Electronic structure modulation of metallic Co via N-doped carbon shell and Cu-doping for enhanced semi-hydrogenation of phenylacetylene to styrene

Styrene, an important monomer in the production of polystyrene, is usually mixed with a small number of phenylacetylene which readily causes the poisoning of catalyst during styrene polymerization. To address this issue, we reported a nitrogen-doped carbon encapsulated CuCo bimetallic catalyst (CuxCo@NC) for styrene production from phenylacetylene semi-hydrogenation. The CuxCo@NC catalyst obtained a 100% conversion of phenylacetylene along with a high 94.6% selectivity of styrene, far higher than those of single metal Co@C and Co@NC catalysts. Detailed characterizations unveiled that the CuxCo@NC catalyst fabricated by a dual-regulation strategy showed Mott-Schottky effect, in which the electrons transferred from metallic Cu to Co and then to outer N-doped carbon shells. Moreover, the electron transfers of metallic Co could be regulated by Mott-Schottky effect with which to improve the semi-hydrogenation of phenylacetylene to styrene. This work provides an feasible pathway to effectively design the supported metal catalysts for highly selective semi-hydrogenation of alkynes to alkenes.

CuI Coordination Polymer‐Catalyzed Azide–Alkyne Cycloaddition Click Reaction at Room Temperature

AbstractFramework based compounds for eco‐friendly catalysis is of utmost industrial interest. CuI‐catalyzed “click” reactions are a class of highly efficient and widely used chemical reactions in organic synthesis for potential applications in biotechnology, medicine, polymer, and material sciences. The importance of click chemistry also acknowledge by 2022 Noble Prize in chemistry. One of the most well‐known click reactions is the copper‐catalyzed azide‐alkyne cycloaddition (CuAAC), which is a type of Huisgen 1,3‐dipolar cycloaddition reaction. Herein, three stable copper(I)‐coordination polymers (CPs), [Cu(4‐ABPT)Cl], CP‐1; [Cu(4‐ABPT)Br], CP‐2; [Cu2(4‐ABPT)0.5I2], CP‐3; (4‐ABPT=3,5‐di(pyridine‐4‐yl)‐4H‐1,2,4‐triazol‐4‐amine) have been chosen for CuAAC reaction, due to presence of both Lewis acidic (copper ion), and basic (pyridyl and amine) sites. The counter anion plays a crucial role in their structural motif as well as catalytic efficiency. These easily synthesizable and scalable catalysts exhibit the trend of CP‐1>CP‐2>CP‐3 in catalysis for the selective conversion of phenylacetylene, benzyl bromide, and sodium azide into 1,4‐cycloaddition product within 2 h at ambient temperature and solvent free reaction conditions. CuAAC reaction using catalyst CP‐1 exhibits near quantitative conversion within 2 h at room temperature in solvent free conditions. Herein, we demonstrated the bulk‐scale synthesis of CuI CPs for efficient azide‐alkyne cycloaddition click reaction under mild reaction conditions.

Efficient selective hydrogenation of terminal alkynes over Pd–Ni nanoclusters encapsulated inside S-1 zeolite

Selective hydrogenation of alkynes is a challenging reaction that requires selective and efficient catalysts to achieve the desired alkenes. The development of general and robust catalysts that can operate under mild conditions and tolerate a wide range of functional groups is still an active area of research. Here, Pd-M bimetallic clusters (M = Ni, Cu, Mn, Fe) encapsulated inside S-1 zeolite were prepared and applied in the selective hydrogenation of substituted terminal alkynes. Among them, the Pd0.6Ni@S-1 catalyst displayed 91 % selectivity to styrene at the full conversion of phenylacetylene. Derivatives of phenylacetylene containing either electron withdrawing/donating or sensitive functional groups were effectively converted into the corresponding alkenes. The confinement effect of zeolite effectively inhibited the over-hydrogenation reaction and enhanced the stability of the catalysts. Furthermore, the product distribution was solvent-dependent by correlating the reaction selectivity with solvent properties. Apolar solvent showed the highest selectivity to styrene in the selective hydrogenation of phenylacetylene due to the competitive adsorption of apolar solvent and styrene on catalysts.

Encapsulation of Palladium Carbide Subnanometric Species in Zeolite Boosts Highly Selective Semihydrogenation of Alkynes.

The selective hydrogenation of alkynes to alkenes is a crucial step in the synthesis of fine chemicals. However, the widely utilized palladium (Pd)-based catalysts often suffer from poor selectivity. In this work, we demonstrate a carbonization-reduction method to create palladium carbide subnanometric species within pure silicate MFI zeolite. The carbon species can modify the electronic and steric characteristics of Pd species by forming the predominant Pd-C4 structure and, meanwhile, facilitate the desorption of alkenes by forming the Si-O-C structure with zeolite framework, as validated by the state-of-the-art characterizations and theoretical calculations. The developed catalyst shows superior performance in the selective hydrogenation of alkynes over mild conditions (298 K, 2 bar H2 ), with 99 % selectivity to styrene at a complete conversion of phenylacetylene. In contrast, the zeolite-encapsulated carbon-free Pd catalyst and the commercial Lindlar catalyst show only 15 % and 14 % selectivity to styrene, respectively, under identical reaction conditions. The zeolite-confined Pd-carbide subnanoclusters promise their superior properties in semihydrogenation of alkynes.

Encapsulation of Palladium Carbide Subnanometric Species in Zeolite Boosts Highly Selective Semihydrogenation of Alkynes

AbstractThe selective hydrogenation of alkynes to alkenes is a crucial step in the synthesis of fine chemicals. However, the widely utilized palladium (Pd)‐based catalysts often suffer from poor selectivity. In this work, we demonstrate a carbonization‐reduction method to create palladium carbide subnanometric species within pure silicate MFI zeolite. The carbon species can modify the electronic and steric characteristics of Pd species by forming the predominant Pd−C4 structure and, meanwhile, facilitate the desorption of alkenes by forming the Si−O−C structure with zeolite framework, as validated by the state‐of‐the‐art characterizations and theoretical calculations. The developed catalyst shows superior performance in the selective hydrogenation of alkynes over mild conditions (298 K, 2 bar H2), with 99 % selectivity to styrene at a complete conversion of phenylacetylene. In contrast, the zeolite‐encapsulated carbon‐free Pd catalyst and the commercial Lindlar catalyst show only 15 % and 14 % selectivity to styrene, respectively, under identical reaction conditions. The zeolite‐confined Pd‐carbide subnanoclusters promise their superior properties in semihydrogenation of alkynes.

Selective hydrogenation of phenylacetylene over high-energy facets exposed nanotubular alumina supported palladium catalysts

High-energy facets exposed nanotubular alumina as well as conventional alumina supported Pd catalysts were synthesized and applied to the selective hydrogenation of phenylacetylene. Novel alumina supported catalyst presented higher selectivity at complete conversion of phenylacetylene. This could be related to the well dispersion of Pd and strong metal-support interaction, which are the consequences of the unique structural properties of the crystal plane regulated alumina. It helps create more active sites for hydrogenation meanwhile facilitates the desorption of alkene and thus suppresses the excess hydrogenation towards ethylbenzene.

Continuous Flow Liquid‐Phase Semihydrogenation of Phenylacetylene over Pd Nanoparticles Supported on UiO‐66(Hf) Metal‐Organic Framework

AbstractCatalysis under continuous flow operation is industrially more relevant compared to reactions carried out in batch reactors. But catalysis with metal‐organic frameworks (MOFs) is largely restricted to batch reactions, especially in case of semi hydrogenation reactions. We anchored Pd nanoparticles (NPs) on robust UiO‐66(Hf) MOF to develop effective catalyst for semi hydrogenation of phenylacetylene into styrene. We investigated catalytic performance of Pd/UiO‐66(Hf) in a continuous‐flow liquid‐phase semi‐hydrogenation of phenylacetylene (PA). In this study, Pd/UiO‐66(Hf) catalyst exhibited good catalytic performance with a rare combination of high PA conversion (99.0 %) and high styrene selectivity (90.0 %). Additionally, Pd/UiO‐66(Hf) demonstrated lower deactivation rate in contrast to many reported materials to date. The higher stability of metal NPs over UiO‐66(Hf) aroused from the strong metal‐support interaction (between Brønsted acidic μ3‐OH of MOF and Pd). The Pd/UiO‐66(Hf) retained its catalytic activity even after four recycles.

Synergistic trimetallic Ni–Cu–Sn catalysts for efficient selective hydrogenation of phenylacetylene

Selective hydrogenation of phenylacetylene is the most effective way to remove a small amount of phenylacetylene from styrene, but it is still a challenge to develop catalysts with high activity and selectivity. Herein, a series of non-precious bimetallic Ni3M/SiO2 (M = Zn, Sn, Cd, Fe, Co, Cu, or Mo) and trimetallic Ni3Cu–Sn/SiO2 catalysts were prepared and applied to selective hydrogenation of phenylacetylene. A trade-off between activity and selectivity was observed on Ni3M/SiO2, where Ni3Cu/SiO2 showed the best hydrogenation activity because of the hydrogen spillover effect of the Ni–Cu alloy, while Ni3Sn/SiO2 exhibited the highest selectivity to styrene due to the active-site isolation effect of the Ni–Sn alloy. Impressively, trimetallic Ni3Cu–Sn/SiO2 offered superior catalytic performance (94 % styrene selectivity at >99 % phenylacetylene conversion) as compared to bimetallic catalysts, owing to the synergistic effect among Ni, Cu, and Sn. In the case of Cu and Sn co-doping, the hydrogen spillover on the Ni–Cu alloy was deeply suppressed by Sn, which enabled an effective modification of the geometric and electronic structures of Ni to favor styrene desorption. The hydrogenation activity of Ni3CuSn0.3/SiO2 can be readily enhanced by increasing the metal loading and further improved by elevating the reaction temperature and pressure, but meanwhile the high selectivity is little affected. This work demonstrates a multi-metal synergistic strategy to break the activity–selectivity trade-off of Ni-based bimetallic catalysts in the selective hydrogenation of alkynes.

Cu-Ce Bimetallic Metal-Organic Framework-Derived, Oxygen Vacancy-Boosted Visible Light-Active Cu2O-CeO2/C Heterojunction: An Efficient Photocatalyst for the Sonogashira Coupling Reaction.

The development of an economical transition metal-based catalyst for photocatalytic carbon-carbon coupling reactions is aspiring. Herein, a Cu-Ce metal-organic framework (MOF) was synthesized and carbonized to produce bimetallic Cu2O-CeO2/C, which was utilized in the Sonogashira cross-coupling reaction. The defects and oxygen vacancies in the catalyst were characterized by X-ray photoelectron spectroscopy and Raman spectroscopy, while the nature of Cu was characterized by H2-TPR analysis. The defect-induced MOF-derived Cu-Ce heterojunction created more oxygen vacancies (OV) in CeO2, revealing the high photocatalytic activity. The Cu-Ce heterojunction (Cu2O-CeO2/C) formed a Cu(I)-phenylacetylide active complex and exhibited higher catalytic activity for the visible light-induced Sonogashira cross-coupling reaction. 25%Cu2O-CeO2/C offered 93.8% phenylacetylene conversion with a 94.2% Sonogashira product selectivity by using household light-emitting diodes. No discernible activity loss was observed from the recycling of the catalyst. Based on catalytic activity, control reactions, and physicochemical and optoelectronic characterization, the structure-activity relationship was established and a reaction mechanism was proposed. Replacement of the costly Pd metal-based catalyst with a cheap Cu2O-CeO2-based catalyst for the synthesis of commercially important compounds with a sustainable visible light-induced catalytic process will be highly attractive to chemists and industrialists.

Preparation of aurum chloride complex and its use for industrial acetylene hydration catalyst process

The use of a modern homogeneous metal complex catalyst for the hydration of acetylenes is being investigated. The process is relevant both for the industry of basic organic synthesis and for the perfume industry. The analysis of existing processes used in industry for the production of acetaldehyde was carried out. Significant shortcomings of existing processes are revealed: low environmental friendliness and high energy consumption. To solve this problem, the reaction of hydration of an acetylene compound was studied using a modern homogeneous catalyst based on gold, which is not toxic. The study was conducted by selecting aliquots during the reaction. Using the 1H NMR spectroscopy method, the conversion values of phenylacetylene were calculated for the time values corresponding to the moments of aliquot sampling. The reaction order with respect to phenylacetylene was calculated and the reaction constant under the reaction conditions was calculated. When reacting in the presence of the proposed catalyst, a conversion of phenylacetylene of 86.96 % is achieved in 3 hours. The data obtained provide grounds for carrying out the process of catalytic hydration of acetylenes, namely phenylacetylene, with the production of acetophenone, which is important for use in the perfume industry. The data obtained can be applied to the process of hydration of acetylene with the formation of acetaldehyde, which is widely used in the industry of basic organic synthesis. For the process of catalytic hydration of acetylene compounds, a hardware design is proposed, a gas-liquid reactor with a changing hydrodynamic situation, which, together with the product separation column, is combined into a single installation. Using an optimized method, a catalyst based on gold chloride was synthesized from a gold alloy.

Unraveling high alkene selectivity at full conversion in alkyne hydrogenation over Ni under continuous flow conditions

Carbon dissolution in Ni lattices decreased the interaction of alkenes with the catalyst surface and gave an elusive combination of full phenyl acetylene conversion and high styrene selectivity (92 ± 1%) under continuous flow conditions.

Promotion Effect of the X-Zeolite Host on Encapsulated Platinum Clusters for Selective Hydrogenation of Phenylacetylene to Styrene.

The microenvironment surrounding the metal clusters on a carrier produces a tremendous influence on its catalytic performance. In this work, the promotion effect of the zeolitic inner host on catalytic performance of encapsulated platinum nanoclusters is reported. In the reaction of phenylacetylene semihydrogenation to styrene, Pt@X-zeolite, where platinum nanoclusters are encapsulated into the inner microporosity of the X-zeolite, exhibits an ∼3.37 times increased turnover frequency and a much better selectivity of 87.6% in comparison to the referenced Pt/X-zeolite of 79.3% selectivity to styrene at the same reaction conditions, in which the platinum nanoclusters are located at the exterior of the zeolite. Meanwhile, the Pt@X-zeolite displays a higher stability after 10 cycles of the reaction. Through the detailed characteristics, the excellent performance of Pt@X-zeolite is mainly due to the promotion of the zeolitic framework on the encapsulated Pt clusters, resulting in "electron-deficient" Pt clusters, leading to a stronger interaction with the π* molecular orbitals of phenylacetylene and thus enhancing the activation and conversion of phenylacetylene. The zeolite cavity wrapped with encapsulated Pt clusters regulates the adsorption trend of phenylacetylene through the acetylene group on it, promotes the desorption of styrene, and strengthens its selectivity. Meanwhile, Pt@X-zeolite has an excellent stability through the zeolite framework, which protects the Pt species from being lost. This investigation reveals the importance of the zeolitic microenvironment on the catalytic performance of encapsulated metal species and deepens the cognition for this type of catalyst.

Mercury Adsorption on Thiol-Modified Porous Boron Nitride: A Combined Experimental and Theoretical Investigation

Heavy metal pollutants from industrial wastewater pose a great threat to public health and ecosystem safety. In this paper, a thiol-modified porous boron nitride (pBN–SH) adsorbent synthesized by a facile acid-etching method was studied for the highly selective adsorption of Hg(II) in a complex environment. pBN–SH was characterized by X-ray diffraction, thermogravimetric, elemental analysis, Brunauer–Emmett–Teller analysis, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, and X-ray photoelectron spectroscopy. The effect of adsorption dosage, pH, contact time, and temperature on Hg(II) adsorption was comprehensively investigated. Characterized results show that thiol groups are loaded on the surface of pBN through oxygen-containing groups and π–π bond. Due to the abundant structural defects and surface modification of functional groups, pBN–SH can effectively capture Hg(II) from water. Compared with the pristine pBN, the adsorption capacity of pBN–SH increases significantly by nearly 2.1 times, which suggests broad application prospects of pBN–SH in removing the Hg(II) aspect. Experimental results corresponding to the pseudo-second-order kinetic, the intra-particle diffusion model, and the Langmuir isotherm demonstrate that pBN–SH holds a high potential in environmental remediation. In addition, the recovered pBN–SH loaded with Hg(II) waste can be available for a valid catalyst for the conversion of phenylacetylene to acetophenone, providing a new way for the reuse of Hg(II)-adsorbed materials. Density functional theory calculations revealed that multitudinous defects and thiol functional groups on the pBN–SH surface, electrostatic attraction, and ligand exchange are responsible for the excellent Hg(II)-selective adsorption capability discovered in the experiment.

Alkyne Hydrogenation Catalysis across a Family of Ga/In Layered Zintl Phases.

Transition-metal-free Zintl-Klemm phases have received little attention as heterogeneous catalysis. Here, we show that a large family of structurally and electronically similar layered Zintl-Klemm phases built from honeycomb layers of group 13 triel (Tr) or group 14 tetrel (Tt) networks separated by electropositive cations (A) and having a stoichiometry of ATr2 or ATrTt (A = Ca, Ba, Y, La, Eu; Tr = Ga, In; Tt = Si, Ge) exhibit varying degrees of activity for the hydrogenation of phenylacetylene to styrene and ethylbenzene at 51 bar H2 and 40-100 °C across a variety of solvents. The most active catalysts contain Ga with, formally, a half-filled pz orbital, and minimal bonding between neighboring Tr2 or TrTt layers. A 13-layer trigonal polytype of CaGaGe (13T-CaGaGe) was the most active, cyclable, and robust catalyst and under modest conditions (1 atm H2, 40 °C) had a surface specific activity (590 h-1) comparable to a commercial Lindlar's catalyst. Additionally, 13T-CaGaGe maintained 100% conversion of phenylacetylene to styrene at 51 bar H2, even after 5 months of air exposure. This work reveals the structural design elements that lead to particularly high catalytic activity in Zintl-Klemm phases, further establishing them as a promising materials platform for hydrogen-based heterogeneous catalysis.

Cu Decorated Rh/TiO2 Catalyst for Selective Hydrogenation of Phenylacetylene to Styrene

AbstractPhenylacetylene as an impurity in styrene is poisonous to catalysts for styrene polymerization in the production of polystyrene plastics. The selective hydrogenation of phenylacetylene to styrene is an industrially promising route to overcome this challenge yet lacks cost‐effective catalysts to prevent the overhydrogenation of styrene to ethylbenzene. In this work, we report an efficient and robust copper‐decorated Rh/TiO2 catalyst for the selective hydrogenation of phenylacetylene to styrene. By optimizing the copper coverage on TiO2 supported Rh nanoparticles, we achieved a selectivity of 83% towards styrene formation at a phenylacetylene conversion of 93%. The appropriate Cu coverage is found to modulate the electronic states of surface Rh atoms and changes the Rh exposed active sites, weakening the binding strength of alkene and hydrogen intermediates on Rh and thus mitigating the overhydrogenation and enhancing the selectivity for styrene generation. This work offers insights on the rational design of efficient Rh‐based bimetallic catalysts for selective hydrogenation of phenylacetylene to styrene.

Silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 as a highly efficient mesoporous solid acid catalyst for the alkenylation of p-xylene with phenylacetylene

Highly dispersed silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 (WZ/SBA-15) as an ordered mesoporous solid acid catalyst was prepared via a facile incipient wetness impregnation (IWI) method that active ingredients, ZrO2 and WO3, were impregnated into the channels of SBA-15 simultaneously with a subsequent calcination process. The relationship between catalyst nature and performance was explored by high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), FT-IR, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature-programmed desorption (NH3-TPD), and FT-IR of pyridine adsorption (Py-IR) characterization techniques. The catalytic performance of W12Z15/SBA-15 is not only greater than that of single component solid acid catalysts, WO3/SBA-15 and ZrO2/SBA-15, but also W12/Z15/SBA-15 prepared by impregnating active ingredients, ZrO2 and WO3, into SBA-15 in sequence. The outstanding performance of W12Z15/SBA-15 is derived from the strong interaction between ZrO2 and WO3, which results in more acid sites, and relatively high specific surface area, large pore volume, and ordered mesoporous structure of SBA-15. The characterization and reaction results clearly demonstrate that the synergy of ZrO2 and WO3 has a clear boost for the alkenylation. The optimized W12Z15/SBA-15-500 achieves a 99.4% conversion of phenylacetylene and a 92.3% selectivity of main product α-arylstyrene for the alkenylation of p-xylene with phenylacetylene, with very low level of oligomers producing at the same time. Moreover, W12Z15/SBA-15-500 shows excellent catalytic stability and regeneration. Therefore, W12Z15/SBA-15-500 is a promising solid acid catalyst for the alkenylation.

Tuning the Pt species on Nb2O5 by support-induced modification in the photocatalytic transfer hydrogenation of phenylacetylene

Herein, we reported the tuning of dominant products in the photocatalytic hydrogen transfer reaction over Pt/Nb2O5 photocatalysts, using a support-induced modification strategy. In the photocatalytic conversion of phenylacetylene with ethanol as a probe reaction, the dominant product was styrene over Pt/2D Nb2O5 nanoplates; in contrast, H2 was the main product over the Pt/bulk Nb2O5. Compared to the metallic Pt species over bulk Nb2O5, the positively charged Pt (Ptδ+) species over 2D Nb2O5 nanoplates contributed to the reduction of phenylacetylene, which was revealed by CO adsorbed Fourier transform infrared spectra. Furthermore, the present Ptδ+ species were due to the formation of Ptδ+–O–Nb structure via oxygen transfer of 2D Nb2O5 nanoplates, which was verified by the results of X-ray photoelectron spectra and H2 temperature-programmed reduction. This work sheds light on the design and application of Nb-based catalysts in the transfer hydrogenation of organics in photocatalysis.

Copper Single-Atom-Covered Pt Nanoparticles for Selective Hydrogenation of Phenylacetylene

The selective hydrogenation of alkynes to alkenes is very important for both industry and scientific investigation, and overhydrogenation of alkynes to alkanes is the biggest problem to be solved. Suppressing the catalytic hydrogenation of alkenes to alkanes and keeping the efficient conversion from alkynes to alkenes at the same time is a viable solution, but the slight difference in structure between alkynes and the corresponding alkenes causes great difficulty in realizing such a target. The Pt/C–Cu bimetallic catalysts are used to catalyze the selective hydrogenation of phenylacetylene (PA) to styrene (ST). High-resolution STEM and EXAFS results show that the prepared Pt/C–Cu catalysts are composed of copper single atoms and Pt nanoparticles. In particular, Pt/C–Cu is a catalyst in which copper single atoms cover the surface of Pt nanoparticles. The experimental results reveal that the selectivity of ST strongly depends on the coverage of Cu single atoms over Pt nanoparticles in Pt/C–Cu, so selective hydrogenation of PA is a structure-sensitive reaction. The selectivity of ST can reach 94.4% at a PA conversion of 100% in the selective hydrogenation of PA over Pt/C–0.5Cu, an optimized Pt–Cu bimetallic catalyst; after selective removal of PA in ST from 100 to 30 ppm over the same catalyst, the yield of ST reaches 99.97%. The chemisorption results of H2 and probe molecule ethene (C2H4) over the Pt–Cu/C catalysts reveal that Cu single atoms covering on the surface of Pt nanoparticles weaken the Pt–H and Pt–C2H4 interactions, so the catalytic hydrogenation of the carbon–carbon double bond over Pt/C–0.5Cu can be tremendously suppressed. The added Cu single atoms over Pt nanoparticles are not poisonous sites because they can also act as the active centers to activate hydrogen and the carbon–carbon double bond.