Nickel catalysts for internal reforming in molten carbonate fuel cells

Natural gas may be used instead of hydrogen as fuel for the molten carbonate fuel cell (MCFC) by steam reforming the natural gas inside the MCFC, using a nickel catalyst (internal reforming). The severe conditions inside the MCFC, however, require that the catalyst has a very high stability. In order to find suitable types of nickel catalysts and to obtain more knowledge about the deactivation mechanism(s) occurring during internal reforming, a series of nickel catalysts was prepared and subjected to stability tests at 973 K in an atmosphere containing steam and lithium and potassium hydroxide vapours. All the catalysts prepared showed a significant growth of the nickel crystallites during the test, especially one based on ¿-Al2O3 and a coprecipitated Ni/Al2O3 sample having a very high nickel content. However, this growth of nickel crystallites only partially explained the very strong deactivation observed in most cases. Only a coprecipitated nickel/alumina catalyst with high alumina content and a deposition-precipitation catalyst showed satisfactory residual activities. Addition of magnesium or lanthanum oxide to a coprecipitated nickel/alumina catalyst decreased the stability.\ud \ud Adsorption and retention of the alkali was the most important factor determining the stability of a catalyst in an atmosphere containing alkali hydroxides. This is because the catalyst bed may remain active if a small part of the catalyst bed retains all the alkali

Ambiguities of resistance and collaboration on the Eastern Cape frontier: the Kat River settlement 1829-1856

This chapter unravels the complexities of resistance to, and collaboration with, the British colonizers of the Eastern Cape, South Africa, by the inhabitants of the Upper Kat River Valley. Since the Khoikhoi landholders of the valley had received their land as a result of British action against the Xhosa, and had generally accepted the precepts of mission Christianity, it could on the one hand be expected that they would fight on the side of the British against the Xhosa. On the other hand, they were subjected to racist attacks by the British settlers whose farms they defended, and by British officials. In addition, the ethnic distinction, on which the British acted, between Xhosa and Khoikhoi was more tenuous than they generally assumed. As a result, in the successive wars on the Eastern Frontier, the stance taken by the Khoikhoi was often uncertain, and finally led to a minority joining the Xhosa, and thus going into rebellion against the British. Notes, ref., sum. [Book abstract]ASC – Publicaties niet-programma gebonde