Surface Modification for Promoting Durable, Efficient, and Selective Electrocatalysts

Abstract

Intensive research into the design of catalysts involved in energy conversion and fuel cell technologies has allowed great progress in the field. However, durable, efficient and selective electrocatalytic systems for the activation of fuel molecules at the lowest cost are still needed. The most developed strategies consist of tailoring the shape, size and composition of metallic nanomaterials. Yet, deliberate surface modification of the catalysts should be considered as a promising alternative approach. The functionalization of metallic catalysts with organic ligands has been recently demonstrated to promote high catalytic activity. This Review focuses on the functionalization of metallic or alloy catalysts with organic ligands, showing the impact of the surface modification for different materials and different reactions. Hybrid systems based on this alternative strategy could contribute to the elaboration of cutting‐edge systems for electrocatalysis.

Transition metal-based catalysts for the electrochemical CO2reduction: from atoms and molecules to nanostructured materials

“…A promising complementary strategy to particle size, shape, composition and support design consists in capping metal NPs with chelating organic molecules. [413][414][415] This alternative approach applies the concepts and tools of conventional coordination chemistry to design novel metal nanocatalysts with improved catalytic properties. In comparison with the traditional strategies to control the structure of metallic NPs, this approach offers a number of additional advantages: (i) the organic capping agents usually act as NPs stabilizers, preventing or minimizing aggregation phenomena and NP oxidation upon air exposure; (ii) the catalytic properties of metal NPs can be tailored by modifying the electronic and structural features of the organic anchoring agent; (iii) tuning of the local environment around the nanocatalyst surface (e.g.…”

“…In general, nanomaterials showed enhanced activity compared to polycrystalline surfaces due to their improved reactivity, conductivity and stability under electrochemical conditions. 414 6.3.1 Thiols. Due to their strong binding affinity for metals, thiolate ligands have been widely employed as stabilizing agents for metal nanostructures, especially on Ag and Au.…”

Selective single-atom electrocatalysts: a review with a focus on metal-doped covalent triazine frameworks

“…Two kinds of selectivity are required in these electrochemical reactions (1) product selectivity (e.g., various products from the CRR): and (2) substrate selectivity (e.g., a methanol-tolerant ORR). 12,13 The control of product selectivity toward high-value-added chemicals is essential because product purication can be drastically simplied, enhancing the technological competitiveness of electrolysis. On the other hand, improving substrate selectivity enables the utilization of contaminated (i.e., low-purity) substrates, which leads to an expansion of electrochemical methods as an on-demand technology.…”

Functionalizing Gold Nanoparticles with Calix[4]arenes Monolayers for Enhancing Selectivity and Stability in ORR Electrocatalysis

“…In line with this concept, the chemical surface modification of metallic nanostructures has just emerged as a promising strategy to increase their catalytic performances as recently reviewed. [ 10 ] Recent reports have highlighted that organic functionalization of metallic nanoparticles can boost their electrocatalytic properties through local interfacial steric or electronic effects. [ 11,12 ] Far from having a detrimental impact, the ligands are found to have a beneficial role.…”

“…The nature of the ligands, [ 13 ] and/or the interfacial bonding, [ 14 ] promote high electrocatalytic activity, selectivity, and durability. [ 10 ] The immobilization of organic molecules to metallic surfaces includes the chemisorption of monomers, polymers or surfactants, the self‐assembly, the covalent grafting or the electrostatic adsorption of charged molecules (e.g., citrates, polyelectrolytes). The strength of interaction between surface and ligands depends on the employed procedures.…”