Visible-Light-Activated Suzuki–Miyaura Coupling Reactions of Aryl Chlorides over the Multifunctional Pd/Au/Porous Nanorods of CeO₂ Catalysts

Activation of aryl chlorides for Suzuki–Miyaura coupling (SMC) reactions is particularly challenging for heterogeneous catalysts due to the chemically inert nature of the C–Cl bond. Herein, the multifunctional Pd/Au/porous nanorods of CeO₂ (<i>PN</i>-CeO₂) catalysts with a well-defined spatial configuration deliver the first example of heterogeneous catalysts to activate the strong C–Cl bond under the irradiation of visible light (>400 nm) at room temperature. <i>PN</i>-CeO₂ with strong basicity not only provides the photogenerated electrons to enrich the electron density of metal nanoparticles but also generates holes for activation of arylboronic acids. Meanwhile, due to the strong local surface plasma resonance, the hot electrons from Au nanoparticles excited by visible light can be injected into Pd nanocatalysts that are spatially contacted with Au nanoparticles. Thus, Pd nanocatalysts with significantly enriched electron density efficiently activate the aryl chlorides under the visible light irradiation at room temperature. The high catalytic activity and reusability of multifunctional photocatalysts associated with full use of the photogenerated electrons and holes inspire the future exploitation for the activation of unreactive chemical bonds under mild conditions

Design of N‑Coordinated Dual-Metal Sites: A Stable and Active Pt-Free Catalyst for Acidic Oxygen Reduction Reaction

We develop a host-guest strategy to construct an electrocatalyst with Fe-Co dual sites embedded on N-doped porous carbon and demonstrate its activity for oxygen reduction reaction in acidic electrolyte. Our catalyst exhibits superior oxygen reduction reaction performance, with comparable onset potential (<i>E</i>_onset, 1.06 vs 1.03 V) and half-wave potential (<i>E</i>_1/2, 0.863 vs 0.858 V) than commercial Pt/C. The fuel cell test reveals (Fe,Co)/N-C outperforms most reported Pt-free catalysts in H₂/O₂ and H₂/air. In addition, this cathode catalyst with dual metal sites is stable in a long-term operation with 50 000 cycles for electrode measurement and 100 h for H₂/air single cell operation. Density functional theory calculations reveal the dual sites is favored for activation of O-O, crucial for four-electron oxygen reduction