An original way to perform the exsolution of Ni nanoparticles on a ceramic support was explored for the development of methane steam reforming catalyst in SOFC anode conditions. The n=2 Ruddlesden‐Popper (RP) phase La1.5Sr1.5Mn1.5Ni0.5O7±δ has been synthesized by the Pechini method and subsequently reduced with an H2‐N2 mixture at different temperatures and reducing times to induce the formation of two phases: LaSrMnO4 (n=1 RP) decorated with metallic Ni nanoparticles. Preliminary measurements of catalytic behavior for the steam reforming have been carried out in a reduction‐reaction process with a mixture of 82 mol %CH4, 18 mol %N2 and low steam to carbon ratio (S/C=0.15). The catalyst exhibits a selectivity for CO production (0.97), 14.60 mol % CH4 conversion and around 24.19 mol % H2 production. Such catalytic behavior was maintained for more than 4 h, with a constant rate of hydrogen production and CH4 conversion rate.

The catalytic behavior of the new Ni exsolved Ruddlesden‐Popper (RP) manganite (La1.5Sr1.5Mn1.5Ni0.5O7) for the reforming reaction was studied. The material was synthesized by the Pechini method and reduced to induce the formation of two phases: n=1 RP structure LaSrMnO4 decorated with Ni nanoparticles. Ni impregnation on (La,Sr)2MnO4 ceramic support of similar composition was also prepared for comparison. The catalytic measurements were carried out in a reduction‐reaction process with low steam to carbon content (S/C=0.15) at 700, 800 and 850 °C. The exsolved material exhibits a better performance than the impregnated for the methane steam reforming reaction, especially at 850 °C with higher conversion and H2 production rate. However, in light alkane gas mixtures (CH4−C2H6 and CH4−C3H8), the behavior is affected due to the competition between reactions and low available metallic active sites, without affecting the H2 production. The exceptional overall results considering this new material as a promising anode material in a SOFC fed with Colombian natural gas.