Shape engineering of palladium aerogels assembled by nanosheets to achieve a high performance electrocatalyst

Yazdan-Abad, Mehdi Zareie; Noroozifar, Meissam; Douk, Abdollatif Shafaei; Modarresi‐Alam, Ali Reza; Saravani, Hamideh

doi:10.1016/j.apcatb.2019.02.064

Cited by 56 publications

(57 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is corroborated that the (111) phase of Pd is less prone to oxidation; therefore, this phase is proper for fuel cell application. 1 …”

Section: Resultsmentioning

confidence: 99%

“…However, commercialization of DEFCs still faces two vital obstacles such as unfavorable durability and inadequate efficiency of catalysts. 1 − 5 Therefore, finding suitable catalysts for electrocatalysis has emerged as a hot topic in the field of materials science. Scientists have dedicated their effort to develop new routes for the development of materials science.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Porous 3D Inorganic Superstructure of Pd–Ir Aerogel as Advanced Support-Less Anode Electrocatalyst toward Ethanol Oxidation

Douk

Saravani

2020

ACS Omega

Self Cite

View full text Add to dashboard Cite

For the first time, synthesis of Pd–Ir aerogel is reported in this manuscript. The Pd–Ir aerogel is synthesized using the controlled assembly of nanoparticles (NPs) (Ir and Pd) during the facile, surfactant-free, fast, and one-step gelation process in an aqueous environment followed by CO 2 supercritical drying. In this process, no chemical reagents are employed to induce the gelation, and change of temperature is employed to create anisotropic electrostatic repulsions between NPs. In addition, the kinetics and the type of product are controlled by the change of temperature. The Pd–Ir aerogel shows a three-dimensional (3D) architecture with a very high porosity and an ultralow density (0.016 g cm –3 ). The Pd–Ir aerogel is applied as an advanced 3D electrocatalyst for the ethanol oxidation reaction (EOR) and offers a remarkable electrocatalytic efficiency (5416.1 mA mg Pd –1 ) in a basic environment. The exceptional electrocatalytic activity and stability of the resultant aerogel are attributed to two crucial reasons: (1) unique structure of Pd–Ir aerogel and (2) synergistic effect of Ir element. Micro- and mesopore characteristics provide a large surface area, while macrospore characteristic guarantees accessibility to active sites. Furthermore, the self-supporting character of the Pd–Ir aerogel may hinder the degradation of durability observed in carbon-based electrocatalysts due to corrosion of carbonaceous support. Moreover, the Ir element as a co-metal in the structure of Pd–Ir aerogel acts as a very efficient promotor in the EOR and can change the electronic structure of Pd, which facilitates the electrooxidation of EtOH in alkaline media.

show abstract

“…It is corroborated that the (111) phase of Pd is less prone to oxidation; therefore, this phase is proper for fuel cell application. 1 …”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Porous 3D Inorganic Superstructure of Pd–Ir Aerogel as Advanced Support-Less Anode Electrocatalyst toward Ethanol Oxidation

Douk

Saravani

2020

ACS Omega

Self Cite

View full text Add to dashboard Cite

show abstract

“…[2][3][4][5][6][7] The high cost, sluggish kinetics and limited reserve of platinum based electrocatalysts are the main hinder for the development and businesslike applications of DAFCs. [10][11][12][13][14][15][16] The stabilities and performance to EOR principally relay on carriers and active components of electrocatalysts. So far, palladium (Pd) catalysts have been proved to be a kind of promising electrocatalysts of EOR for lower cost, higher electrocatalytic property in the alkaline solution.…”

Section: Introductionmentioning

confidence: 99%

“…So far, palladium (Pd) catalysts have been proved to be a kind of promising electrocatalysts of EOR for lower cost, higher electrocatalytic property in the alkaline solution. [10][11][12][13][14][15][16] The stabilities and performance to EOR principally relay on carriers and active components of electrocatalysts. [17][18][19][20][21] For palladium based catalysts, it is imperative to explore other electrocatalyst carriers with specific structure and component characteristic.…”

Section: Introductionmentioning

confidence: 99%

Palladium Nanoparticles Supported on B‐Doped Carbon Nanocage as Electrocatalyst toward Ethanol Oxidation Reaction

Yao

Zhang

et al. 2019

ChemElectroChem

View full text Add to dashboard Cite

Boron-doped carbon nanocage (BC-2) was used as carrier to anchor palladium nanoparticles and enhanced the catalytic performance for the ethanol oxidation reaction. The BC-2 was synthesized via thermal treatment the predesigned compound containing cobalt and boron at 900°C with the help of hydrogen and acid washing process. Palladium nanoparticles can be loaded on the BC-2 supports (Pd/BC-2) for ethanol oxide reaction (EOR). The BC-2 support has the following character-istics: (i) The hollow structure contains highly order nanoporous to offer more channel and space in catalysis process; (ii) borondoped carbon structures can supply abundant activity sites for stabilizing palladium nanoparticles; (iii) the unique three-dimensional architecture can prevent the agglomeration and inactivation of metal catalysts. The Pd/BC-2 catalyst displays higher catalytic activities 3614.11 mA mg À 1 toward the peak current density compared to that of Pd/C (804.39 mA mg À 1 ).

show abstract

“…[95][96][97] Similarly, when palladium acetylacetonate, monocarboxylic acid (R-COOH) with different alkyl group, and CO act as precursor, solvent, and reducing agent, respectively, Pd 4 (CO) 4 (RCOO) 4 in which four Pd atoms are in the same plane would be obtained, and result in the final Pd aerogels with ultrathin Pd nanosheets (Figure 10c,d). [98,99] Besides, longer alkyl chain possesses stronger capping and aggregation suppression capability, and nanosheets with thickness of 2 and 7 nm are synthesized by propionic acid and acetic acid, respectively. Furthermore, as stated earlier, the synthesized nanosheet can be transformed into nanomesh through solution-based oxidative etching.…”

Section: Anisotropic Growth and Orientation Adhesionmentioning

confidence: 99%

Porous Noble Metal Electrocatalysts: Synthesis, Performance, and Development

Chen

2021

Small

View full text Add to dashboard Cite

Benefiting from the various structures of channel, skeleton, and pore wall, porous materials are more valuable than nonporous and ultra-small counterparts in practical applications. In regard to porous catalyst, higher surface area logically means more exposed active sites, and reasonable channel structure ensures the accessibility of active sites. Optimization of pore structure, which includes pore size, pore dimensions, and the pore size distributions, would bring enhanced catalytic activity. Besides, to a certain extent, compared with ultra-fine or ultrasmall nanocrystals, porous catalysts constructed by primary particles have higher stability to ensure maximum retention of active sites, and the increased stability can be attributed to the suppression of Ostwald ripening. Meanwhile the influence of porous structure on the catalytic selectivity cannot be ignored, for instance, microporous materials have a shape-selective catalytic effect on reactants, intermediates, and products of different sizes. In porous materials with larger pores, for catalytic reactions with multi-stage reaction products, the mass transfer Active sites (intrinsic activity, quantity, and distribution), electron transfer, and mass diffusion are three important factors affecting the performance of electrocatalysts. Composed of highly active components which are built into various network structures, porous noble metal is an inherently promising electrocatalysts. In recent years, great efforts have been made to explore new efficient synthesis methods and establish structural-performance relationships in the field of porous noble metal electrocatalysis. In this review, the very recent progress in strategies for preparing porous noble metal, including innovation and deeper understanding of traditional methods is summarized. A discussion of relationship between porous noble metal structure and electrocatalytic performance, such as accessibility of active sites, connectivity of skeleton structures, channels dimensions, and hierarchical structures, is provided. rate affected by the shape and dimensions of the pores can also affect the diffusion rate of the primary reaction products and improve the selectivity of the secondary reaction products. [1] For solid catalysts, the species and coordination state of surface atoms could influence the intrinsic activity of active sites, and in porous materials with tortuous channel structure and rough pore wall, atoms with different coordination states exposed on the pore wall would exert different abilities to adsorb and activate reactant molecules.Noble metals possess suitable electronic structures, which gives it a significant innate advantage of excellent catalytic activity and stability. From the perspective of d-band center theory, proper d-band center positions of the noble metals give rise to a moderate chemical adsorption strength for the reactants, intermediate species, and products during the catalytic process. This means noble metals can adsorb and activate the reactant molecules moderately while...

show abstract

Shape engineering of palladium aerogels assembled by nanosheets to achieve a high performance electrocatalyst

Cited by 56 publications

References 36 publications

Porous 3D Inorganic Superstructure of Pd–Ir Aerogel as Advanced Support-Less Anode Electrocatalyst toward Ethanol Oxidation

Porous 3D Inorganic Superstructure of Pd–Ir Aerogel as Advanced Support-Less Anode Electrocatalyst toward Ethanol Oxidation

Palladium Nanoparticles Supported on B‐Doped Carbon Nanocage as Electrocatalyst toward Ethanol Oxidation Reaction

Porous Noble Metal Electrocatalysts: Synthesis, Performance, and Development

Contact Info

Product

Resources

About