Metal‐oxo Cluster Mediated Atomic Rh with High Accessibility for Efficient Hydrogen Evolution

Abstract

Achieving single‐atom catalysts (SACs) with high metal content and outstanding performance as well as robust stability is critically needed for clean and sustainable energy. However, most of the synthesized SACs are undesired on the loading content of the metal due to the anchored metals and the supports as well as the synthesizing methods. Herein, a Rh‐SAC with high accessibility by loading it on the metal nodes of metal‐porphyrin‐based PCN MOFs (PCN‐224) as supporting material is reported. Significantly, the PCN‐Rh15.9/KB catalyst with a high Rh content of 15.9 wt% exhibits excellent hydrogen evolution activity with a low overpotential of 25 mV at a current density of 10 mA cm−2 and a mass activity of 7.7 A mg−1Rh at overpotential of 150 mV, which is much better than that of the commercial Rh/C. Various characterizations reveal the Rh species is stabilized by the metal nodes bearing −O/OHx in MOFs, which is of importance for the high loading amount and the good activity. This work establishes an efficient approach to synthesize high content SACs on the nodes of MOFs for wide catalyst design.

Atomically Structured Metal‐Organic Frameworks: A Powerful Chemical Path for Noble Metal‐Based Electrocatalysts

“…In the stability test, >20 h hydrogen evolving was achieved from acidic seawater at the current density of 10 mA cm −2 . [ 49 ] This work establishes an efficient way to fabricate performed‐well SACs with high noble metal loadings through single‐atom engineering on nodes of MOFs. Here, the HER performances of representative MOF‐stabilized/derived NMECs are summarized in Table 4 .…”