scispace - formally typeset
Search or ask a question
Author

Duan-Hui Si

Bio: Duan-Hui Si is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Electrocatalyst & Reversible hydrogen electrode. The author has an hindex of 4, co-authored 5 publications receiving 68 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, a conductive two-dimensional (2D) phthalocyanine-based MOF (NiPc-NiO4 ) nanosheets linked by nickel-catecholate was proposed for the CO2 electroreduction reaction (CO2 RR) to CO.
Abstract: The electrocatalytic conversion of CO2 into value-added chemicals is a promising approach to realize a carbon-energy balance. However, low current density still limits the application of the CO2 electroreduction reaction (CO2 RR). Metal-organic frameworks (MOFs) are one class of promising alternatives for the CO2 RR due to their periodically arranged isolated metal active sites. However, the poor conductivity of traditional MOFs usually results in a low current density in CO2 RR. We have prepared conductive two-dimensional (2D) phthalocyanine-based MOF (NiPc-NiO4 ) nanosheets linked by nickel-catecholate, which can be employed as highly efficient electrocatalysts for the CO2 RR to CO. The obtained NiPc-NiO4 has a good conductivity and exhibited a very high selectivity of 98.4 % toward CO production and a large CO partial current density of 34.5 mA cm-2 , outperforming the reported MOF catalysts. This work highlights the potential of conductive crystalline frameworks in electrocatalysis.

158 citations

Journal ArticleDOI
TL;DR: In this paper, an earth-abundant elements-based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel-nitrogen sites for the enhanced CO2 RR to produce C2 H4.
Abstract: Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO2 RR towards C2 H4 by multiple distinct catalytic sites in local vicinity. An earth-abundant elements-based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel-nitrogen sites (PTF(Ni)) for the enhanced CO2 RR to produce C2 H4 . The Faradaic efficiency of C2 H4 reaches 57.3 % at -1.1 V versus the reversible hydrogen electrode (RHE), which is about 6 times higher than the non-tandem catalyst PTF/Cu, which produces CH4 as the major carbon product. The operando infrared spectroscopy and theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni) sites can facilitate the C-C coupling to form C2 H4 on the nearby Cu NP sites. The work offers an effective avenue to design electrocatalysts for the highly selective CO2 RR to produce multicarbon products via a tandem route.

102 citations

Journal ArticleDOI
01 Dec 2020-Small
TL;DR: This work presents the implementation of the conductive COF nanosheets for CO2 RR and provides a strategy to enhance energy conversion efficiency in electrocatalysis.
Abstract: The electroreduction of CO2 to value-added chemicals such as CO is a promising approach to realize carbon-neutral energy cycle, but still remains big challenge including low current density. Covalent organic frameworks (COFs) with abundant accessible active single-sites can offer a bridge between homogeneous and heterogeneous electrocatalysis, but the low electrical conductivity limits their application for CO2 electroreduction reaction (CO2 RR). Here, a 2D conductive Ni-phthalocyanine-based COF, named NiPc-COF, is synthesized by condensation of 2,3,9,10,16,17,23,24-octa-aminophthalocyaninato Ni(II) and tert-butylpyrene-tetraone for highly efficient CO2 RR. Due to its highly intrinsic conductivity and accessible active sites, the robust conductive 2D NiPc-COF nanosheets exhibit very high CO selectivity (>93%) in a wide range of the applied potentials of -0.6 to -1.1 V versus the reversible hydrogen electrode (RHE) and large partial current density of 35 mA cm-2 at -1.1 V versus RHE in aqueous solution that surpasses all the conventional COF electrocatalysts. The robust NiPc-COF that is bridged by covalent pyrazine linkage can maintain its CO2 RR activity for 10 h. This work presents the implementation of the conductive COF nanosheets for CO2 RR and provides a strategy to enhance energy conversion efficiency in electrocatalysis.

91 citations

Journal ArticleDOI
TL;DR: In this paper, surface ionization of an imidazolium-functionalized framework with a sterically hindered poly(ethylene glycol) sulfonate (PEGS) canopy was used for the fabrication of a MOF liquid (Im-UiO-PL).
Abstract: The unique applications of porous metal-organic framework (MOF) liquids with permanent porosity and fluidity have attracted significant attention. However, fabrication of porous MOF liquids remains challenging because of the easy intermolecular self-filling of the cavity or the rapid settlement of porous hosts in hindered solvents that cannot enter their pores. Herein, we report a facile strategy for the fabrication of a MOF liquid (Im-UiO-PL) by surface ionization of an imidazolium-functionalized framework with a sterically hindered poly(ethylene glycol) sulfonate (PEGS) canopy. The Im-UiO-PL obtained in this way has a CO2 adsorption approximately 14 times larger than that of pure PEGS. Distinct from a porous MOF solid counterpart, the stored CO2 in Im-UiO-PL can be slowly released and efficiently utilized to synthesize cyclic carbonates in the atmosphere. This is the first example of the use of a porous MOF liquid as a CO2 storage material for catalysis. It offers a new method for the fabrication of unique porous liquid MOFs with functional behaviors in various fields of gas adsorption and catalysis.

71 citations

Journal ArticleDOI
TL;DR: In this paper, a two-dimensional (2D) Ni-phthalocyanine-based MOF (NiPc-Ni(NH)4) constructed by 2,3,9,10,16,17,23,24-octaaminophthalocyaninato nickel(II) and nickel ions attained high electrical conductivity due to the high overlap of d-π conjugation orbitals between the nickel node and o-phenylenediamine.
Abstract: Porous crystalline metal-organic frameworks (MOFs) are one class of promising electrode materials for CO2 electroreduction reaction (CO2RR) by virtue of their large CO2 adsorption capacities and abundant tunable active sites, but their insulating nature usually leads to low current density. Herein, a two-dimensional (2D) Ni-phthalocyanine-based MOF (NiPc-Ni(NH)4) constructed by 2,3,9,10,16,17,23,24-octaaminophthalocyaninato nickel(II) (NiPc-(NH2)8) and nickel(II) ions attained high electrical conductivity due to the high overlap of d-π conjugation orbitals between the nickel node and the Ni-phthalocyanine-substituted o-phenylenediamine. During CO2RR, the NiPc-Ni(NH)4 nanosheets achieved a high CO Faradaic efficiency of 96.4% at −0.7 V and a large CO partial current density of 24.8 mA cm−2 at −1.1 V, which surpassed all the reported two-dimensional MOF electrocatalysts evaluated in an H-cell. The control experiments and density functional theory (DFT) calculations suggested that the Ni-N4 units of the phthalocyanine ring are the catalytic active sites. This work provides a new route to the design of highly efficient porous framework materials for the enhanced electrocatalysis via improving electrical conductivity.

49 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In this article, a conductive two-dimensional (2D) phthalocyanine-based MOF (NiPc-NiO4 ) nanosheets linked by nickel-catecholate was proposed for the CO2 electroreduction reaction (CO2 RR) to CO.
Abstract: The electrocatalytic conversion of CO2 into value-added chemicals is a promising approach to realize a carbon-energy balance. However, low current density still limits the application of the CO2 electroreduction reaction (CO2 RR). Metal-organic frameworks (MOFs) are one class of promising alternatives for the CO2 RR due to their periodically arranged isolated metal active sites. However, the poor conductivity of traditional MOFs usually results in a low current density in CO2 RR. We have prepared conductive two-dimensional (2D) phthalocyanine-based MOF (NiPc-NiO4 ) nanosheets linked by nickel-catecholate, which can be employed as highly efficient electrocatalysts for the CO2 RR to CO. The obtained NiPc-NiO4 has a good conductivity and exhibited a very high selectivity of 98.4 % toward CO production and a large CO partial current density of 34.5 mA cm-2 , outperforming the reported MOF catalysts. This work highlights the potential of conductive crystalline frameworks in electrocatalysis.

158 citations

Journal ArticleDOI
TL;DR: In this paper, an earth-abundant elements-based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel-nitrogen sites for the enhanced CO2 RR to produce C2 H4.
Abstract: Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO2 RR towards C2 H4 by multiple distinct catalytic sites in local vicinity. An earth-abundant elements-based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel-nitrogen sites (PTF(Ni)) for the enhanced CO2 RR to produce C2 H4 . The Faradaic efficiency of C2 H4 reaches 57.3 % at -1.1 V versus the reversible hydrogen electrode (RHE), which is about 6 times higher than the non-tandem catalyst PTF/Cu, which produces CH4 as the major carbon product. The operando infrared spectroscopy and theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni) sites can facilitate the C-C coupling to form C2 H4 on the nearby Cu NP sites. The work offers an effective avenue to design electrocatalysts for the highly selective CO2 RR to produce multicarbon products via a tandem route.

102 citations

Journal ArticleDOI
TL;DR: In this paper, surface ionization of an imidazolium-functionalized framework with a sterically hindered poly(ethylene glycol) sulfonate (PEGS) canopy was used for the fabrication of a MOF liquid (Im-UiO-PL).
Abstract: The unique applications of porous metal-organic framework (MOF) liquids with permanent porosity and fluidity have attracted significant attention. However, fabrication of porous MOF liquids remains challenging because of the easy intermolecular self-filling of the cavity or the rapid settlement of porous hosts in hindered solvents that cannot enter their pores. Herein, we report a facile strategy for the fabrication of a MOF liquid (Im-UiO-PL) by surface ionization of an imidazolium-functionalized framework with a sterically hindered poly(ethylene glycol) sulfonate (PEGS) canopy. The Im-UiO-PL obtained in this way has a CO2 adsorption approximately 14 times larger than that of pure PEGS. Distinct from a porous MOF solid counterpart, the stored CO2 in Im-UiO-PL can be slowly released and efficiently utilized to synthesize cyclic carbonates in the atmosphere. This is the first example of the use of a porous MOF liquid as a CO2 storage material for catalysis. It offers a new method for the fabrication of unique porous liquid MOFs with functional behaviors in various fields of gas adsorption and catalysis.

71 citations

Journal ArticleDOI
TL;DR: In this article, the structure and composition of phthalocyanines (Pcs), methods of synthesis of Pcs and their analogues, as well as applications of Pc-based heterogeneous electrocatalysts are discussed.
Abstract: Applications of phthalocyanines (Pcs) in electrocatalysis—including the oxygen reduction reaction (ORR), the carbon dioxide reduction reaction (CO2RR), the oxygen evolution reaction (OER), and the hydrogen evolution reaction (HER)—have attracted considerable attention recently. Pcs and their derivatives are more attractive than many other macrocycles as electrocatalysts since, although they are structurally related to natural porphyrin complexes, they offer the advantages of low cost, facile synthesis and good chemical stability. Moreover, their high tailorability and structural diversity mean Pcs have great potential for application in electrochemical devices. Here we review the structure and composition of Pcs, methods of synthesis of Pcs and their analogues, as well as applications of Pc-based heterogeneous electrocatalysts. Optimization strategies for Pc-based materials for electrocatalysis of ORR, CO2RR, OER and HER are proposed, based on the mechanisms of the different electrochemical reactions. We also discuss the structure/composition–catalytic activity relationships for different Pc materials and Pc-based electrocatalysts in order to identify future practical applications. Finally, future opportunities and challenges in the use of molecular Pcs and Pc derivatives as electrocatalysts are discussed.

67 citations

Journal ArticleDOI
TL;DR: In this article , the effect of the geometric construction and electronic configuration of 2D MOFs and their derivatives on the electrocatalytic performance is detailedly discussed by combining experimental achievements and theoretical analysis.

63 citations