“…In a similar manner, the minor local expansion of the SOD cages around 820 K could also be a response to coke accumulation as there is no second event in the NH 3 related m/z trace ( Figure 5). During the in situ experiments, the powder took on a yellow tint between 473 and 523 K, its tone became darker as the temperature increased, then turned to black and finally white above 900 K. Coke formation leading to unit cell volume expansion has been observed for ZSM-5, SAPO-34 and SAPO-18 [29,[33][34][35][36]. It is worth noticing that the unit cell shrinkage observed in this temperature region is attributed to two different, synergetic mechanisms: the template removal that physically empties the space in the sodalite chages and the material's intrinsic negative thermal expansion.…”