Octahedral core–shell bimetallic catalysts M@UIO-67 (M = Pt–Pd nanoparticles, Pt–Pd nanocages): Metallic nanocages that enhanced CO2 conversion

Zhang, Huaqian; Xu, Heng; Li, Yuanyuan; Su, Yuqun

doi:10.1016/j.apmt.2020.100609

Cited by 19 publications

(7 citation statements)

References 71 publications

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“…Scholars are devoting tremendous efforts toward the development of sustainable energy technologies to mitigate our reliance on fossil fuels or their associated emissions. Electrochemical CO 2 reduction (CO 2 R) into chemicals and fuels is one promising approach under investigation. − Through CO 2 R, renewable energy resources such as solar, wind, or hydro could be utilized to generate the required electricity for driving the reduction reaction. CO 2 R can be carried out under near-ambient conditions, restraining the need for high-temperature and/or high-pressure operation. − …”

Section: Introductionmentioning

confidence: 99%

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg²⁺ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO₂

Ismail

Abdellah

Sudheeshkumar

et al. 2022

ACS Appl. Energy Mater.

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Electrochemical CO2 reduction (CO2R) is a promising avenue for the conversion of CO2 into fuels and beneficial chemicals. Significant efforts have been devoted to the development of active and selective electrocatalysts for CO2R. Atomically dispersed transition metal electrocatalysts have recently attracted consideration for CO2R due to their unique electronic and structural properties that can impart good catalytic performance and high active metal utilization. Among different precursors used for preparing these catalysts, metal–organic frameworks (MOFs) have been utilized as templates for generating atomically dispersed transition metal active sites as they provide well-defined structures that contain transition metals isolated from each other by organic ligands, along with high surface areas. However, maintaining the isolation of the transition metal species, achieving high surface concentrations of active sites, and imparting porosity during the high-temperature heat treatment of MOFs used during synthesis remain a challenge. In this report, Mg2+ ions have been employed as spacers in a bimetallic metal–organic framework (NiMg-MOF-74) to assist in preventing the coalescence of the Ni atoms into Ni-based particles during heat treatment, which combined with the use of urea as a nitrogen source resulted in the formation of isolated Ni–N x /C active sites. Our findings demonstrated that Mg2+ ions play a crucial role in extending the distance between the adjacent Ni sites in the precursor structure and generating atomically isolated Ni sites. On the contrary, the utilization of Mg-free Ni-MOF-74 led to the formation of metallic Ni particles embedded in a carbon nanotube-based structure. Furthermore, we investigated the impact of pyrolysis temperature on the produced catalyst morphology. The generation of isolated Ni–N x /C sites was promoted at higher pyrolysis temperatures (900 °C), while Ni-based particles were predominantly formed at a lower temperature (700 °C). The optimized atomically dispersed Ni–N–C catalyst exhibited excellent selectivity toward CO with a Faradaic efficiency of ∼90% and a current density of −4.2 mA/cm2 at −0.76 V vs a reversible hydrogen electrode.

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Section: Introductionmentioning

confidence: 99%

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg²⁺ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO₂

Ismail

Abdellah

Sudheeshkumar

et al. 2022

ACS Appl. Energy Mater.

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“…[1][2][3][4][5] MOFs offer a wide range of active sites including exchangeable coordination positions around the metal ions, acid or basic substituents on the organic linker or active guests incorporated within the empty voids. [6][7][8][9][10][11][12] In addition, MOFs may exhibit photoresponse and they are among the most active photocatalysts for aerobic oxidations, [13][14][15][16][17] overall water splitting [18][19][20][21] and CO2 reduction [22][23][24][25][26] among other reactions. 27 The presence of more than one active site renders MOFs very suited hybrid catalysts to promote tandem reactions in which more than elementary conversion.…”

Section: Introductionmentioning

confidence: 99%

Bifunctional metal–organic frameworks for the hydrogenation of nitrophenol using methanol as the hydrogen source

et al. 2021

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“…PVP is an amphiphilic, nonionic polymer, which is extensively used as a capping agent to control the size and shape of various NPs and stabilize them . On the other hand, PVP confers the Pt NPs with enhanced affinity to the growing UiO-66 surface through the coordination interaction between polar groups (pyrrolidone ring and CO) and zirconium atoms in UiO-66 nodes, and also through hydrophobic interaction between nonpolar groups (carbon chain) and organic linkers. − …”

Section: Resultsmentioning

confidence: 99%

Breaking the Activity-Selectivity Trade-Off of Pt Nanoparticles Encapsulated in UiO-66 for Hydrogenation by Constructing Suitable Hierarchical Structure

Guo

Zhang

et al. 2022

ACS Sustainable Chem. Eng.

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The simultaneous enhancement of activity and selectivity during hydrogenation is a great challenge. Herein, by encapsulating Pt nanoparticles (NPs) into the hierarchical defective metal−organic framework (MOF) of UiO-66, the steric screening effect of the pores, Lewis acid sites of the nodes, and metal-MOF synergy have been finely tuned and effectively utilized for selective hydrogenation. Benefiting from optimal meso/micropores, favorable Lewis acid sites and strengthened metal−support interaction, Pt NPs encapsulated in hierarchical UiO-66 exhibited superior performance in selective hydrogenation. With the proper loading of Pt NPs into suitable meso/microporous UiO-66, the conversion of cinnamaldehyde is increased from 18.2% to 85% along with the selectivity for cinnamyl alcohol being improved from 15.8% to 76% under 70 °C and 2 MPa. The conventional trade-off relationship between increasing selectivity and promoting activity for encapsulated metal catalysts has been broken with the as-developed catalyst. This study provides a promising strategy to optimize transformation efficiency by the design of a tailored MOF-based framework for encapsulating metal NPs with the needed steric effect and synergistic effect.

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Octahedral core–shell bimetallic catalysts M@UIO-67 (M = Pt–Pd nanoparticles, Pt–Pd nanocages): Metallic nanocages that enhanced CO2 conversion

Cited by 19 publications

References 71 publications

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg²⁺ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO₂

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg²⁺ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO₂

Bifunctional metal–organic frameworks for the hydrogenation of nitrophenol using methanol as the hydrogen source

Breaking the Activity-Selectivity Trade-Off of Pt Nanoparticles Encapsulated in UiO-66 for Hydrogenation by Constructing Suitable Hierarchical Structure

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Octahedral core–shell bimetallic catalysts M@UIO-67 (M = Pt–Pd nanoparticles, Pt–Pd nanocages): Metallic nanocages that enhanced CO2 conversion

Cited by 19 publications

References 71 publications

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg2+ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO2

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg2+ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO2

Bifunctional metal–organic frameworks for the hydrogenation of nitrophenol using methanol as the hydrogen source

Breaking the Activity-Selectivity Trade-Off of Pt Nanoparticles Encapsulated in UiO-66 for Hydrogenation by Constructing Suitable Hierarchical Structure

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Octahedral core–shell bimetallic catalysts M@UIO-67 (M = Pt–Pd nanoparticles, Pt–Pd nanocages): Metallic nanocages that enhanced CO2 conversion

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg²⁺ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO₂

Atomically Isolated Nickel–Nitrogen–Carbon Electrocatalysts Derived by the Utilization of Mg²⁺ ions as Spacers in Bimetallic Ni/Mg–Metal–Organic Framework Precursors for Boosting the Electroreduction of CO₂