Promotional Effects of Mg-Substituted Ni/Mg( x )HAP Catalysts on Carbon Resistance during Dry Reforming of Methane

Supported Ni-based catalysts were easily sintered anddeactivatedin the dry re-forming of methane (DRM), resulting from a weak metal-supportinteraction. To solve this problem, a series of Mg-substituted hydroxyapatite(HAP) catalysts (Ni/Mg( x )HAP, x = 0, 0.5, 1, 1.5) with 3% Ni loaded were prepared by partial substitutionof Ca in HAP by Mg and used for DRM. The results showed that the presenceof Mg influenced the formation and growth of HAP, resulting in latticedistortion and the formation of a large number of lattice defectsin HAP, thus promoting Ni entry into the HAP lattice, and the amountof Ni2+[II] in the HAP lattice increased. Ni2+[II] in the lattice did not easily sinter at a high temperature,and the Ni average particle size of the Ni/Mg(1)HAP catalystwas the smallest (7.5 nm) after reduction at 700 & DEG;C; in addition,the specific surface area of the catalyst increased after Mg substitution.After a 100 h stability test, the Ni/Mg(1)HAP catalyst maintainedhigh catalytic activity. In situ infrared studies showed that Ni/Mg(1)HAP inhibited the formation of monodentate carbonate and prevented deactivation of the catalyst caused by the coverage of active sites.

Automated summary

Supported Ni-based catalysts were easily sintered and deactivated in the dry re-forming of methane. Mg-substituted hydroxyapatite (HAP) catalysts (Ni/Mg(x)HAP, x = 0, 0.5, 1, 1.5) with 3% Ni loaded were prepared to solve this problem. The presence of Mg in the HAP lattice promoted Ni entry and inhibited carbonate formation, leading to enhanced catalytic activity and stability.