Pd single atom stabilized on multiscale porous hollow carbon fibers for phenylacetylene semi-hydrogenation reaction

• Design efficient hierarchical 1D Pd SACs by co-axial emulsion electrospinning. • The obtained 1D SACs have multiscale porous hollow structure like bamboo. • The bamboo-like structure is facility for increasing catalytic activity. • Single atom improves selectivity of phenylacetylene semi-hydrogenation. • The method is universal for many other hierarchical 1D metal SACs (Pt, Ru, Co). The extremely high atom dispersion of single atom catalysts (SACs) opens up new opportunities for highly efficient catalysis. However, how to balance the easy accessibility, preparation simplicity, and recoverability for routine nanoscale catalytic supports of SACs is still a big challenge. In this work, the nitrogen doped carbon immobilized Pd SACs with high loading up to 5.6 wt.%, in the form of multiscale porous hollow fibers, are prepared through a co-axial emulsion electrospinning and CO 2 thermal activating method. The obtained Pd SACs carbon fibers have a bamboo-like tubular structure and multiscale pores on the tube wall, which expose the active sites accessible for reactants. The multiscale porous hollow Pd SACs exhibited both high activity and selectivity for phenylacetylene semi-hydrogenation. This universal method is also applicable for the preparation of many other 1D metal SACs such as Pt, Ru and Co, which exhibits great promising for developing easily available and efficient SACs.