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  Ru clusters anchored on ultrathin TiO2 NBs with rich oxygen vacancies are fabricated.
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  Ru/TiO2 NBs achieve up to 80 % alanine yield from lignocellulose-derived lactic acid.
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  The oxygen vacancies in TiO2 enable the α-OH dehydrogenation occur spontaneously.
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  The Ru clusters dominate the dehydrogenation from the α-OH and α-C(sp3)-H of LA.
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  The Ru clusters are beneficial for the dehydrogenation and hydrogenation performance.

Amino acids are widely used in various applications, its production mainly relies on the fermentation of grain crops, and the chemosynthesis method from non-grain biomass still faces the challenge of low efficiency (<50 %). Herein, Ru clusters anchored on ultrathin TiO2 nanobelts (NBs) with abundant oxygen vacancies are fabricated and used to convert lignocellulose-derived α-hydroxy acids to α-amino acids. The Ru/TiO2 NBs achieved up to 80 % alanine yield from lignocellulose-derived lactic acid (LA). The characterization results reveal that the TiO2 NBs with abundant oxygen vacancies could anchor Ru clusters uniformly and enable the α-OH dehydrogenation occur spontaneously. Simultaneously, Ru clusters with appropriate particle size are beneficial for the activation of H2 and could promote the dehydrogenation from the α-OH and α-C(sp3)-H of LA. Furthermore, DFT simulations also indicate that further decrease the Ru cluster size (< 1 nm) will inhibit the adsorption of α-C(sp3)-H on cluster surface, thereby suppressing the removal of hydrogen atoms. This research provides a green and efficient chemical catalytic conversion idea for amino acid production from non-grain biomass.