Biomass Derivative Valorization Using Nano Core-Shell Magnetic Materials Based on Keggin-Heteropolyacids: Levulinic Acid Esterification Kinetic Study with N-Butanol

Table 1

Textural properties of the different solids studied.

Entry	Solid	(m^2 g^-1)	^a (nm)
1	Fe3O4	6	—
2	Fe3O4@SiO2	20	8
3	Fe3O4@SiO2@SiO2/TPASC	65	7
4	Fe3O4@SiO2@SiO2/TPA400N2	45	9

^aAverage pore diameter estimated from S_BET.