Pd nanoparticles anchored on porous boron nitride nanofibers as highly active and stable electrocatalysts for formic acid oxidation

Abstract

Direct formic acid fuel cells (DFAFCs) are promising power generation technologies for various electronic devices. The design of efficient and stable electrocatalysts for the formic acid oxidation reaction (FAOR) plays an important role for the commercial applications of the DFAFCs. Herein, porous boron nitride (BN) supported Pd nanoparticles (NPs) have been developed as unique and effective composite catalysts for FAOR. Porous BN nanofibers (BNNFs) has been utilized as a functional support to anchor of Pd NPs. The high specific surface area and rich porosity of BNNFs play a key role for the well-dispersion and stabilization of Pd NPs with uniform ultra-small size (~2.32 nm) on their surface. The developed Pd/BNNFs composite catalyst exhibits excellent catalytic activity for FAOR with the mass activity of 725 mA mg−1Pd and a very low onset potential (about −0.12 V). Comparative experiments confirm that the microstructure of porous BN carrier greatly affects the electrocatalytic behaviors of the composite catalyst in FAOR. As compared with the composite catalyst using BN microfibers (BNMFs) as a support, the developed Pd/BNNFs catalyst shows superior catalytic activity and long-term stability owing to the larger specific surface area of BNNFs and stronger interaction between Pd NPs and support. This study not only illustrates that porous BN is a desirable catalyst carrier for catalytic FAOR but also provides new ideas for the design of novel BN-based catalysts.