Stable Trimetallic NiFeCu Catalysts with High Carbon Resistance for Dry Reforming of Methane
Feikai Jin, Yu Fu, Wenbo Kong, Jiyang Wang, Fufeng Cai, Changkun Yuan, Bingrong Pan, Jun Zhang, Yuhan Sun
Abstract
Abstract Copper has been incorporated into Ni−Fe alloys to form a series of ternary NiFeCu alloy catalysts with molar ratio of Cu/Fe varying from 0 to 1.5, which were tested in dry reforming of methane (DRM) at 923 K and atmospheric pressure with a CH 4 /CO 2 ratio of 1. XRD, TPR‐H 2 and FE‐TEM measurements confirm the formation of Ni−Fe−Cu alloys with particle size of 5.0‐5.7 nm. The Ni 3 Fe 1 Cu 1 ‐Mg x Al y O z (2.6 wt% Cu) shows the highest carbon resistance with only 5.0 % carbon by thermogravimetric analysis. Importantly, XPS analyses complemented with XAFS demonstrate that doping an appropriate quantity of Cu to form stable trimetallic alloy enhances the interaction between Ni and Fe, thus inhibiting Fe segregation and reducing carbon deposition. However, doping excessive Cu (3.9 wt%) weakens the Ni−Fe bond, preventing Fe from providing labile oxygen to Ni sites, which is unfavorable for carbon elimination.