Influence of Pt addition to Ni catalysts on the catalytic performance for long term dry reforming of methane

The influence of Pt addition (in very low concentrations) to a Ni/(10%)/Al2O3 catalyst in its catalytic performance during long-term experiments of dry reforming of methane was studied.The monometallic Pt(0.5%)/Al2O3 catalyst displayed a pronounced deactivation during 6500 min reaction time, mainly due to a significant sintering of the metallic phase, whereas the monometallic Ni(10%)/Al2O3 catalyst showed a high and stable activity along the reaction time.Compared with the Ni(10%)/Al2O3 catalyst, the bimetallic Ni(10%)Pt(0.5%)/Al2O3 sample showed a higher, and stable catalytic activity during the 6500 min reaction time and a markedly lower carbon deposition. TEM images reveal much less carbon formation and filament grow and this leads to expect a higher stability in long term processes. Characterization techniques indicate that nickel and platinum are in close contact during the simultaneous reduction of the two oxide precursors and that geometric effects (dilution and blocking) are mainly responsible for the excellent catalytic behaviour of the bimetallic NiPt catalyst.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (125 K)Download as PowerPoint slideHighlights► Pt was added to a Ni(10%)/Al2O3 to test its performance in a long-term dry reforming of methane. ► Pt(0.5%)/Al2O3 displayed a pronounced deactivation due to a sintering of the metallic phase. ► Ni(10%)/Al2O3 showed high and stable activity. ► Ni(10%)Pt(0.5%)/Al2O3 showed higher, stable activity and lower carbon deposition. ► The behaviour of the NiPt catalyst is due to geometric effects.