Hydrogen Bubble Templated Metal Foams as Efficient Catalysts of CO₂ Electroreduction

Abstract

The creation of open porous structures with an extremely high surface area is of great technological relevance. The electrochemical deposition of metal foams around co‐generated hydrogen bubbles that act as templates for the deposition is a promising, cheap and simple approach to the fabrication of new electrocatalyst materials. Metal foams obtained by dynamic hydrogen bubble templating (DHBT) offer an intrinsically high electrical conductance with an open porous structure that enables the fast transport of gases and liquids. As an additional benefit, the confined space within the pores of DHBT metal foams may act as small reactors that can harbour reactions not possible at an open electrode interface. The number, distribution, and size of the pores can be fine‐tuned by an appropriate choice of the electrolysis parameters so that metal foam catalysts prepared by the DHBT technique meet certain requirements. In this paper, we review the preparation of certain metal foams, and their applications as catalysts for the electrochemical reduction of CO2.

Insights from Operando and Identical Location (IL) Techniques on the Activation of Electrocatalysts for the Conversion of CO2: A Mini-Review

“…2) that are used in gas-fed electrolyzer systems that can reach ec-CO 2 RR current densities of technological relevance (> 200 mA × cm -2 ). [13,14] A relatively new and alternative concept of ec-CO 2 RR catalyst design relies on the electrodeposition of foam-type materials [11,[15][16][17] (Fig. 2), which, similar to their nanoparticulate counterparts, offer a large surface area that is not only accessible to reactants but also enables fast, multidimensional electron transport.…”

“…2), which, similar to their nanoparticulate counterparts, offer a large surface area that is not only accessible to reactants but also enables fast, multidimensional electron transport. [17] Moreover, self-standing foams can directly be employed as cathodes for the ec-CO 2 RR often without the need for additional mechanical support, rendering the application of conductive binders unnecessary. [17] Herein we review and compare the structural, compositional and performance characteristics of two prototypical foam electrocatalysts that are based on Cu and Bi systems published recently.…”

“…[17] Moreover, self-standing foams can directly be employed as cathodes for the ec-CO 2 RR often without the need for additional mechanical support, rendering the application of conductive binders unnecessary. [17] Herein we review and compare the structural, compositional and performance characteristics of two prototypical foam electrocatalysts that are based on Cu and Bi systems published recently. [11,[18][19][20] Among various materials studied so far, Cu stands out as the only known mono-metallic catalyst that can produce multiple hydrocarbons and alcohols of various chain lengths at elevated rates from the ec-CO 2 RR.…”

Beyond Copper: Novel Ni Foam Catalysts for Sustainable Nitrate to Ammonia Electroreduction

“…23,28 A clear advantage of this classical approach is that the entire spectrum of mature colloid chemistry can be applied to synthesize nano-objects with various shapes, morphologies, and size distributions. Herein, we introduce and apply an alternative concept of NO 3 − RR catalyst fabrication based on an additive-and template-assisted metal electrodeposition route 34,35,41 , which is demonstrated to be highly versatile and complementary to the common colloid approach of catalyst design. Metal foams offer a large surface area that not only is accessible to reactants but also enables fast, multi-dimensional electron transport pathways.…”

Electrochemical Reduction of Carbon Dioxide on 3D Printed Electrodes

“…[19] Copper electroplating performed at elevated current density magnitudes is accompanied by hydrogen evolution reaction and leads to dendrites clustered in sponge-like structures. [20][21][22][23] Electrochemical cycling of copper substrates leads to nanocubes [24,25] and trenches [25] while thermal annealing of these substrates creates microwires, [21,[26][27][28] microflakes [29] and nanopores. [27] The application of these synthetic approaches to substrates with controlled microarchitectures represents a way to manufacture tailored catalysts for the CO 2 electroreduction.…”