Bimetallic Rh–Ni/BN catalyst for methane reforming with CO2

The dry reforming of methane (CH4) with carbon dioxide (CO2) was carried out using bimetal (Rh–Ni)-loaded boron nitride (BN) and γ-Al2O3 catalysts. The incipient wetness method was used to load different ratios of Rh/Ni on BN and γ-Al2O3 supports. The metal particles were too small to be observed in the XRD indicating highly dispersed Rh–Ni particles on the supports. XPS results showed that, after H2 reduction at 500 °C, Rh became metallic element while most Ni remained in its oxidized state. The addition of Rh increased the activity of dry reforming as well as the stability of the catalysts. In general, the conversions of CH4 with CO2 on Rh–Ni/BN catalysts were higher than those on Rh–Ni/γ-Al2O3 catalysts. The optimum ratio of Rh/Ni loading on BN was 0.01. The ratio of H2 and CO as the products was near 0.7. The maximum conversions of CH4 and CO2 reached 72% and 81%, respectively, at 700 °C, while only slight deactivation was observed after 6 h of reaction time. Boron nitride has many unique properties, such as inertness and negligible metal-support interference, as compared with traditional oxide supports. Metal particles can migrate freely and easily to form Rh–Ni clusters on the BN surface. This may be the origin of the activity enhancement in dry reforming.