Tuning donor–acceptor interactions via electronic modulation in Ga-doped ZnO for carbon chain growth from syngas

Abstract

Higher alcohol synthesis from syngas over conventional CuZn catalysts often encounters a trade-off between total alcohol selectivity and C 2 + distribution. Here, we show that Ga-doped ZnO enables precise electronic modulation to balance donor and acceptor reactions through controlled Ga doping. Electron-deficient Zn δ+ sites serve as key active centers, facilitating non-dissociative CO adsorption and CO insertion for carbon chain growth. At low doping, substitutional Ga acts as a donor, promoting C-O bond activation. At 1 mol% Ga, substitutional Ga and the resulting electron-deficient Zn δ+ sites effectively balance the electron donation-acquisition relationship, achieving 63.5% liquid C 2 + alcohol content. Excessive doping (13 mol%) causes Ga clustering and electron-rich states, over-dominating acceptor reactions and suppressing CO insertion. This work establishes that balancing donor–acceptor reactions via electronic modulation is key to overcoming this trade-off, offering a design principle extendable to other electronically tunable catalytic systems.