Heterogeneous Tin Catalysts Applied to the Esterification and Transesterification Reactions

Table 2

Activation energy for NH₃ desorption, BET surface, and crystal size for super acid sulfated tin oxide catalysts [19]^a.

Catalyst activation	Activation energy (kJ/mol)	Correlation factor (𝑅^2)	BET (surface area)	Crystal size (nm)
SnO2	5.69	0.9540	8.32	60.7
SO4^2−/SnO2, 300°C	7.25	0.9687	6.77	42.9
SO4^2−/SnO2, 400°C	7.18	0.9715	—	59.6
SO4^2−/SnO2, 500°C	6.01	0.9877	—	62.0
SO4^2−/SnO2-SiO2, 300°C	9.40	0.9991	13.90	47.7
SO4^2−/SnO2-Al2O3, 300°C	7.51	0.9925	14.04	45.4

aNH₃-TPD patterns for different samples of catalyst at a ramping rate of 10°C min⁻¹ which allowed calculating the NH₃ desorption activation energy (adapted from [19]).