Hao Zhang

Achieving high‐density single‐atom catalysts (SACs) remains a fundamental challenge, particularly for precious metals such as Ru that readily aggregate under synthetic and catalytic conditions. Here, we report a rational precursor design strategy for fabricating high‐density Ru SACs via direct carbonization, yielding ordered carbonaceous frameworks (Ru‐OCFs) with high Ru loadings of up to 11.0 wt%. By expanding the scope of precursors for OCF synthesis beyond conventional macrocyclic coordination motifs to coordinatively flexible polypyridyl ligands, we show that Ru‐terpyridine crystals with thermally polymerizable ethynyl units serve as effective precursors for immobilizing single‐atomic Ru species within three‐dimensional porous carbon frameworks, without metal aggregation or post‐synthetic treatments. The resulting Ru‐OCFs retain the ordered structure and coordination environment of the precursor crystals while simultaneously developing microporosity with high specific surface areas of up to 670 m ² g ⁻¹ . As a proof of concept, the high‐density isolated Ru sites in Ru‐OCFs enable enhanced catalytic activity in liquid‐phase CO ₂ hydrogenation, achieving a high formic acid productivity of up to 19 mmol g _cat ⁻¹ h ⁻¹ , outperforming representative nanoparticle catalysts.

Achieving high‐density single‐atom catalysts (SACs) remains a fundamental challenge, particularly for precious metals such as Ru that readily aggregate under synthetic and catalytic conditions. Here, we report a rational precursor design strategy for fabricating high‐density Ru SACs via direct carbonization, yielding ordered carbonaceous frameworks (Ru‐OCFs) with high Ru loadings of up to 11.0 wt%. By expanding the scope of precursors for OCF synthesis beyond conventional macrocyclic coordination motifs to coordinatively flexible polypyridyl ligands, we show that Ru‐terpyridine crystals with thermally polymerizable ethynyl units serve as effective precursors for immobilizing single‐atomic Ru species within three‐dimensional porous carbon frameworks, without metal aggregation or post‐synthetic treatments. The resulting Ru‐OCFs retain the ordered structure and coordination environment of the precursor crystals while simultaneously developing microporosity with high specific surface areas of up to 670 m ² g ⁻¹ . As a proof of concept, the high‐density isolated Ru sites in Ru‐OCFs enable enhanced catalytic activity in liquid‐phase CO ₂ hydrogenation, achieving a high formic acid productivity of up to 19 mmol g _cat ⁻¹ h ⁻¹ , outperforming representative nanoparticle catalysts.