Fig. 3

Catalytic performance of the catalysts. a Reaction pathway of the hydrogenation of 4-nitrophenylacetylene (4-NPA). b The catalytic performance of PtZn/HNCNT, Pt/HNCNT, hollow nitrogen-doped carbon nanotube (HNCNT), Pt/CN, and ZnO

Catalytic performance of the catalysts. a Reaction pathway of the hydrogenation of 4-nitrophenylacetylene (4-NPA). b The catalytic performance of PtZn/HNCNT, Pt/HNCNT, hollow nitrogen-doped carbon nanotube (HNCNT), Pt/CN, and ZnO