Porphyrinic Metal‐Organic Frameworks Derived Carbon‐Based Nanomaterials for Hydrogen Evolution Reaction

Abstract

Abstract Hydrogen is a renewable, secure and environmentally friendly source of energy, and thus it is important to find an effective way to prepare hydrogen evolution reaction (HER) catalysts. Herein, we report a strategy to prepare noble metal‐decorated porous carbon‐based nanomaterials by direct carbonization of porphyrinic metal‐organic frameworks of M‐PCN‐222(Hf) that are also denoted as M‐PMOF‐2(Hf) (M=Rh, Ir or Pt) at an elevated temperature under an Ar atmosphere. The M‐PCN‐222(Hf) samples with the nanorod shape are synthesized by the self‐assembly of M‐TCPP (TCPP=tetrakis(4‐carboxyphenyl)porphyrin) and HfCl 4 , and the noble metals within the frameworks are uniformly dispersed at the atomic level. Through pyrolysis at 600, 700 or 800 °C and followed by acid etching with HF, noble metal‐decorated porous carbon‐based nanomaterials that are termed as M‐PCN‐222(Hf)‐T (T is the pyrolysis temperature) are obtained, in which the noble metal nanoparticles are dispersed uniformly within the porphyrin ligand‐derived nitrogen‐doped carbon matrix. Inheriting the structural characteristics of the MOF template, M‐PCN‐222(Hf)‐T display relatively high BET surfaces up to 310 m 2 ⋅g −1 and large mesopores with an average pore diameter around 6 nm. Catalytic results show that the prepared M‐PCN‐222(Hf)‐T samples display high HER catalytic activities in a 0.5 M H 2 SO 4 solution (pH=0.36).