Exposing an Environmentally Friendly Gelation Strategy to Fabricate Modern Three-Dimensional M–Ag (M = Pt and Pd) Aerogels with Excellent Green Energy Generation

Abstract

Developing high-performance electrocatalysts has become a critical challenge in sustainable energy field. Compared with previous research, this contribution exposes a new insight and a fully green gelation strategy to fabricate modern three-dimensional aerogels without surfactants or reducing agents. The Pd−Ag and Pt−Ag aerogels are fabricated by inducing controlled anisotropic atmospheres between the resulting NPs from irreversible spontaneous redox reactions followed by CO 2 supercritical drying. Additionally, the kinetics and thermodynamic concepts relevant to the synthesis mechanisms are deeply discussed. Based on analyses, two unique superstructures with enormous surface areas and many open interconnected tunnels are constructed. These advanced aerogels demonstrated encouraging efficiency for decomposing CH 3 CH 2 OH against Pd/C because of the following reasons. The contact of CH 3 CH 2 OH molecules with the outer and inner sites of aerogels is ensured due to their macroscopic nature. Interestingly, the self-supporting nature of modern superstructures ensures sustainability, as they do not have the drawbacks of carbon-based catalysts. Moreover, the presence of Ag as an oxophilic metal not only alters the electronic properties (synergistic effects) of Pt and Pd but also facilitates the adsorption of OH −1 species on the electrocatalyst surface. Hence, this issue promotes the decomposition of CH 3 CH 2 OH and effectively prevents poisoning by CO.