Novel amorphous Ni-B catalysts supported on alumina have been developed for the production of hydrogen peroxide from carbon monoxide, water and oxygen. The experimental investigation confirmed that the promoter/Ni ratio and the preparation conditions have a significant effect on the activity and lifetime of the catalyst. Among all the catalysts tested, the Ni-La-B/gamma-Al2O3 catalyst with a 1:15 atomic ratio of La/Ni, dried at 120degreesC, shows the best activity and lifetime for the production of hydrogen peroxide. The deactivation of the alumina-supported Ni-B amorphous catalyst was also studied. According to the characterizations of the fresh and used catalysts by SEM, XRD and XPS, no sintering of the active component and crystallization of the amorphous species were observed. However, it is water poisoning that leads to the deactivation of the catalyst. The catalyst characterization demonstrated that the active component had changed (i.e., amorphous NiO to amorphous Ni(OH)(2)) and then salt was formed in the reaction conditions. Water promoted the deactivation because the surface transformation of the active Ni species was accelerated by forming Ni(OH)(2) in the presence of water. The formed Ni(OH)(2) would partially change to Ni-3 (PO4)(2) (C) 2003 Elsevier B.V. All rights reserved.