scholarly journals Carbon Monoxide Promotes the Catalytic Hydrogenation on Metal Cluster Catalysts

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ruixuan Qin ◽  
Pei Wang ◽  
Pengxin Liu ◽  
Shiguang Mo ◽  
Yue Gong ◽  
...  

Size effect plays a crucial role in catalytic hydrogenation. The highly dispersed ultrasmall clusters with a limited number of metal atoms are one candidate of the next generation catalysts that bridge the single-atom metal catalysts and metal nanoparticles. However, for the unfavorable electronic property and their interaction with the substrates, they usually exhibit sluggish activity. Taking advantage of the small size, their catalytic property would be mediated by surface binding species. The combination of metal cluster coordination chemistry brings new opportunity. CO poisoning is notorious for Pt group metal catalysts as the strong adsorption of CO would block the active centers. In this work, we will demonstrate that CO could serve as a promoter for the catalytic hydrogenation when ultrasmall Pd clusters are employed. By means of DFT calculations, we show that Pdn n=2‐147 clusters display sluggish activity for hydrogenation due to the too strong binding of hydrogen atom and reaction intermediates thereon, whereas introducing CO would reduce the binding energies of vicinal sites, thus enhancing the hydrogenation reaction. Experimentally, supported Pd2CO catalysts are fabricated by depositing preestablished [Pd2(μ-CO)2Cl4]2- clusters on oxides and demonstrated as an outstanding catalyst for the hydrogenation of styrene. The promoting effect of CO is further verified experimentally by removing and reintroducing a proper amount of CO on the Pd cluster catalysts.

2020 ◽  
Author(s):  
hao yin ◽  
Liqing Zheng ◽  
Wei Fang ◽  
Yin-Hung Lai ◽  
Nikolaus Porenta ◽  
...  

<p>Understanding the mechanism of catalytic hydrogenation at the local environment requires chemical and topographic information involving catalytic sites, active hydrogen species and their spatial distribution. Here, tip-enhanced Raman spectroscopy (TERS) was employed to study the catalytic hydrogenation of chloro-nitrobenzenethiol on a well-defined Pd(sub-monolayer)/Au(111) bimetallic catalyst (<i>p</i><sub>H2</sub>=1.5 bar, 298 K), where the surface topography and chemical fingerprint information were simultaneously mapped with nanoscale resolution (≈10 nm). TERS imaging of the surface after catalytic hydrogenation confirms that the reaction occurs beyond the location of Pd sites. The results demonstrate that hydrogen spillover accelerates hydrogenation at the Au sites within 20 nm from the bimetallic Pd/Au boundary. Density functional theory was used to elucidate the thermodynamics of interfacial hydrogen transfer. We demonstrate that TERS as a powerful analytical tool provides a unique approach to spatially investigate the local structure-reactivity relationship in catalysis.</p>


2020 ◽  
Author(s):  
Hao Yin ◽  
Liqing Zheng ◽  
Wei Fang ◽  
Yin-Hung Lai ◽  
Nikolaus Porenta ◽  
...  

<p>Understanding the mechanism of catalytic hydrogenation at the local environment requires chemical and topographic information involving catalytic sites, active hydrogen species and their spatial distribution. Here, tip-enhanced Raman spectroscopy (TERS) was employed to study the catalytic hydrogenation of chloro-nitrobenzenethiol on a well-defined Pd(sub-monolayer)/Au(111) bimetallic catalyst (<i>p</i><sub>H2</sub>=1.5 bar, 298 K), where the surface topography and chemical fingerprint information were simultaneously mapped with nanoscale resolution (≈10 nm). TERS imaging of the surface after catalytic hydrogenation confirms that the reaction occurs beyond the location of Pd sites. The results demonstrate that hydrogen spillover accelerates hydrogenation at the Au sites within 20 nm from the bimetallic Pd/Au boundary. Density functional theory was used to elucidate the thermodynamics of interfacial hydrogen transfer. We demonstrate that TERS as a powerful analytical tool provides a unique approach to spatially investigate the local structure-reactivity relationship in catalysis.</p>


Nanoscale ◽  
2021 ◽  
Author(s):  
Wei Bing ◽  
Faming Wang ◽  
Yuhuan Sun ◽  
Jinsong Ren ◽  
Xiaogang Qu

An environmentally friendly biomimetic strategy has been presented and validated for the catalytic hydrogenation reaction in live bacteria. In situ formed ultra-fine metal nanoparticles can realize highly efficient asymmetric hydrogenation reactions.


2020 ◽  
Author(s):  
Ioannis Spanos ◽  
Justus Masa ◽  
Aleksandar Zeradjanin ◽  
Robert Schlögl

AbstractThere is an ongoing debate on elucidating the actual role of Fe impurities in alkaline water electrolysis, acting either as reactivity mediators or as co-catalysts through synergistic interaction with the main catalyst material. This perspective summarizes the most prominent oxygen evolution reaction (OER) mechanisms mostly for Ni-based oxides as model transition metal catalysts and highlights the effect of Fe incorporation on the catalyst surface in the form of impurities originating from the electrolyte or co-precipitated in the catalyst lattice, in modulating the OER reaction kinetics, mechanism and stability. Graphic Abstract


2017 ◽  
Vol 5 (39) ◽  
pp. 20789-20796 ◽  
Author(s):  
Mingwei Zhang ◽  
Guozhu Li ◽  
Xiaoqing Sun ◽  
Yujiao Jiang ◽  
Xiangwen Zhang

A joint experimental–theoretical study has been conducted to investigate the role of polydopamine as an interface facilitator for supported noble metal catalysts.


2020 ◽  
Author(s):  
Yi Shi ◽  
Wenmao Huang ◽  
Jian Li ◽  
Yue Zhou ◽  
Zhongqiu Li ◽  
...  

<p>The growth of atomically dispersed metal catalysts (ADMCs) remains a great challenge owing to the thermodynamically driven atom aggregation. Here we report a surface-limited electrodeposition technique that uses site-specific substrates for the rapid and room-temperature synthesis of ADMCs. We obtained ADMCs by the underpotential deposition (UPD) of a single-atom nonnoble metal onto the chalcogen atoms of chemically exfoliated transition metal dichalcogenides and subsequent galvanic displacement with a more-noble single-atom metal. The site-specific electrodeposition (SSED) enables the formation of energetically favorable metal–support bonds, and then automatically terminates the sequential formation of metallic bonding. The self-terminating effect restricts the metal deposition to the atomic scale. The modulated ADMCs exhibit remarkable activity and stability in the hydrogen evolution reaction compared to state-of-the-art single-atom electrocatalysts. We demonstrate that this SSED methodology could be extended to the synthesis of a variety of ADMCs (for example, Pt, Pd, Rh, Cu, Pb, Bi, and Sn single atoms), showing its general scope for the large-scale production of functional ADMCs in heterogenous catalysis. </p>


2020 ◽  
Author(s):  
Yi Shi ◽  
Wenmao Huang ◽  
Jian Li ◽  
Yue Zhou ◽  
Zhongqiu Li ◽  
...  

<p>The growth of atomically dispersed metal catalysts (ADMCs) remains a great challenge owing to the thermodynamically driven atom aggregation. Here we report a surface-limited electrodeposition technique that uses site-specific substrates for the rapid and room-temperature synthesis of ADMCs. We obtained ADMCs by the underpotential deposition (UPD) of a single-atom nonnoble metal onto the chalcogen atoms of chemically exfoliated transition metal dichalcogenides and subsequent galvanic displacement with a more-noble single-atom metal. The site-specific electrodeposition (SSED) enables the formation of energetically favorable metal–support bonds, and then automatically terminates the sequential formation of metallic bonding. The self-terminating effect restricts the metal deposition to the atomic scale. The modulated ADMCs exhibit remarkable activity and stability in the hydrogen evolution reaction compared to state-of-the-art single-atom electrocatalysts. We demonstrate that this SSED methodology could be extended to the synthesis of a variety of ADMCs (for example, Pt, Pd, Rh, Cu, Pb, Bi, and Sn single atoms), showing its general scope for the large-scale production of functional ADMCs in heterogenous catalysis. </p>


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