Li2ZrO3 modified with molten salts as potential materials for CO elimination: Effect of carbonate type and oxygen addition

It has been evaluated the effect of different types of carbonates on the catalytic activity of Li2ZrO3 during CO oxidation. Pure Li2ZrO3 was synthesized and me-chanically modified with alkaline or metallic carbonates. Pure Li2ZrO3 and sodium-containing materials showed similar catalytic activity between 490 and 530 degrees C but not better than the pristine sample. Catalytic results under different O2/CO ratios showed that CO oxidation was not favored without O2, regardless of the catalyst used. A gas stream with excess O2 increments the catalytic performance, allowing to reach CO2 formations between 80 and 99% with pure and Li2ZrO3-NiCO3 samples, respectively. The most favorable effect due to NiCO3 addition was the reduction in the temperature for CO oxidation. Thus, the catalytic performance of the Ni-modified ceramic was the best, reaching conversions of 63 and 75% in low-and moderate-temperature ranges. None of these carbonate-modified materials captured the formed CO2.

Automated summary

The effect of different types of carbonates on the catalytic activity of Li2ZrO3 during CO oxidation was evaluated. Pure Li2ZrO3 and carbonate-modified samples showed similar catalytic activity, but not better than the pristine sample. CO oxidation was not favored without O2, and excess O2 improved the catalytic performance and CO2 formation. The addition of NiCO3 reduced the temperature for CO oxidation and enhanced the catalytic performance of the Ni-modified ceramic.