Poly(4-hydroxybutyrate) (P4HB) is a high-performance, well-recyclable, and biodegradable polyhydroxyalkanoate (PHA). However, conventional bioproduction of homopolymeric P4HB involves complex and costly processes with C4 feedstocks, particularly 1,4-butanediol (BDO), and enzyme-coenzyme systems in genetically engineered bacteria. An alternative extracellular chemical route utilizing aerial oxidation of BDO offers cost and energy benefits but struggle with conversion efficiency. Inspired by efficient intracellular oxidation of primary alcohols, we propose a ruthenium-phosphine synergistic catalytic system that mimics enzyme-coenzyme functionality. This system effectively catalyzed the air-mediated, solvent-free oxidation of BDO to produce γ-butyrolactone (γ-BL) and oligomeric P4HB, with a space-time yield (10.37 g [γ-BL unit] g