Catalyst (10% by weight)

Rate constant $k\left(h_r^{-1}\right)$ at 650˚C

CaO

2.438 × 10⁻³

Fe₂O₃

3.640 × 10⁻³

None

4.250 × 10⁻³

CuO

1.014 × 10⁻²

NaCl

4.849 × 10⁻²

KCl

1.116 × 10⁻¹

Li₂CO₃

1.670 × 10⁻¹

Na₂CO₃

3.154 × 10⁻¹

K₂CO₃

5.388 × 10⁻¹