The　auto-thermal　reforming　(ATR)　of　acetic　acid　is　an　effective　hydrogen　production　method,　but　it　suffers　from　catalyst　deactivation　by　coking.　Sm-promoted　layered　La2NiO4　perovskite　catalysts　were　synthesized　via　the　sol-gel　method　and　its　catalytic　performance　in　the　ATR　of　HAc　was　further　evaluated.　The　characterization　results　demonstrate　that　the　incorporation　of　Sm　into　the　lattice　of　La2NiO4　perovskite　led　to　the　formation　of　Ni-La-Sm-O　species,　inducing　crystal　defects　in　the　perovskite　structure　which　could　promote　the　gasification　of　coking　precursors.　Additionally,　Sm　regulated　the　reduction　characteristics　of　La2NiO4,　resulting　in　the　formation　of　highly　dispersed　nickel　nanoparticles　upon　the　hydrogen　reduction,　which　increased　the　number　of　active　sites　available　for　acetic　acid　conversion.　Consequently,　a　stable　reactivity　without　obvious　coking　was　obtained　over　a　Ni0.42La0.7Sm0.36O2.01　+/-delta　catalyst　within　the　ATR　of　Hac.　The　hydrogen　yield　reached　2.53　mol-H-2/mol-HAc　along　with　the　complete　conversion　of　acetic　acid.