fig2

Figure 2. CH₄-TPSR-MS results in the presence of gaseous O₂ over the (A) SrSnO₃ and (B) Nd₂Sn₂O₇. Reaction conditions: CH₄/O₂/He = 4/1/5, (Ar as balance gas), WHSV = 18,000 mL·h^-1·g^-1. TPSR: Temperature-programmed surface reaction; MS: mass spectrometry; WHSV: weight hourly space velocity.