In this study, the potential of attapulgite (ATTP) as the support of nickel catalysts for steam reforming of acetic acid to produce hydrogen were evaluated. Ni/Al2O3 was prepared and evaluated for comparison. The results showed that ATTP had a much lower specific surface area and a lower thermal stability than alumina. Nevertheless, the interaction between nickel and ATTP was much weaker than that of nickel with alumina. As a result, the Ni/ATTP catalyst had superior activity than the Ni/Al(2)O(3)catalyst, especially at low nickel loading. Ni./Al2O3 was more stable than Ni/ATTP. The fibrous coke, which was probably catalytic coke, formed over Ni/Al2O3 did not cause the rapid deactivation of the catalyst, while the amorphous coke formed over Ni/ATTP catalyst, which was probably the polymeric coke, rapidly deactivated the catalyst. The coke species contained COOH, C=O, aliphatic structure and aromatic ring structures. In addition, the effects of these two carriers on the steam reforming mechanism were investigated by the in-situ DRIFTS. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.