Alves, Melquizedeque B.; Medeiros, Fernando C. M.; Sousa, Marcelo H.; Rubim, Joel C.; Suarez, Paulo A. Z.

doi:10.5935/0103-5053.20140238

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Articles • J. Braz. Chem. Soc. 25 (12) • Dez 2014 • https://doi.org/10.5935/0103-5053.20140238 copiar

Cadmium and Tin Magnetic Nanocatalysts Useful for Biodiesel Production

Autoria SCIMAGO INSTITUTIONS RANKINGS

Nanopartículas magnéticas compostas por óxidos mistos de ferro/cádmio (ICdO) e ferro/ estanho (ISnO) foram usadas como catalisadores em reações relevantes para diferentes tecnologias de produção de biodiesel. Estes compostos foram ativos para hidrólise e transesterificação de óleo de soja, bem como para a esterificação de ácidos graxos obtidos a partir do óleo de soja. Na esterificação mediada por ISnO foram alcançados altos rendimentos, ca. 84%, após 1 h de reação a 200 ºC. O óxido foi recuperado magneticamente e reutilizado quatro vezes sem perda da sua atividade catalítica, enquanto que uma perda significativa foi observada quando ICdO foi usado. ISnO demonstrou também atividade para a produção de biodiesel a partir de óleo de macaúba, um substrato altamente ácido.

		Before reaction		After reaction
		Before reaction	Transesterification	Esterification	Hydrolysis
ICdO	Catalyst recovered^a a Percentage (m/m) of catalyst recovered after the fourth recycle; / %	-	79	71	74
	Molar (Fe/Cd) ratio^b b determined by ICP-AES;	3.7	10.1	50.3	67.0
	d_XR^c c note that these results may be not precise because of the relatively low resolution of the spectra. / nm	3.5	7.9	13.7	20.9
	a / Å	8.37	8,41	8.39	8.40
ISnO	Catalyst recovered^a a Percentage (m/m) of catalyst recovered after the fourth recycle; / %	-	87	90	89
	Molar (Fe/Sn) ratio^b b determined by ICP-AES;	3.3	3.4	3.3	3.4
	d_XR^c c note that these results may be not precise because of the relatively low resolution of the spectra. / nm	34.8	36.2	34.7	33.3
	a /Å	8.38	8.45	8.44	8.42

	Surface area^a a Multipoint Brunauer-Emmett-Teller (BET). / (m² g^-1)	Total pore volume / (cm³ g^-1)	Average pore radius / nm
ICdO	130.2	0.206	3.169
ISnO	49.9	0.0968	3.883

Solids used as catalytic precursor	Recycle No.	Transesterification		Esterification		Hydrolysis
Solids used as catalytic precursor	Recycle No.	M²⁺ / ppm	Iron / ppm	M²⁺ / ppm	Iron / ppm	M²⁺ / ppm	Iron / ppm
ICdO	0	4831^a a ppm of cadmium, determined by ICP-AES;	893	4570^a a ppm of cadmium, determined by ICP-AES;	276	4580^a a ppm of cadmium, determined by ICP-AES;	354
	1	354^a a ppm of cadmium, determined by ICP-AES;	90	829^a a ppm of cadmium, determined by ICP-AES;	43	402^a a ppm of cadmium, determined by ICP-AES;	129
	2	139^a a ppm of cadmium, determined by ICP-AES;	57	259^a a ppm of cadmium, determined by ICP-AES;	14	67^a a ppm of cadmium, determined by ICP-AES;	110
	3	79^a a ppm of cadmium, determined by ICP-AES;	21	135^a a ppm of cadmium, determined by ICP-AES;	24	46^a a ppm of cadmium, determined by ICP-AES;	72
	4	60^a a ppm of cadmium, determined by ICP-AES;	5	85^a a ppm of cadmium, determined by ICP-AES;	6	54^a a ppm of cadmium, determined by ICP-AES;	10
ISnO	0	15^b b ppm of tin, determined by ICP-AES;	4	20^b b ppm of tin, determined by ICP-AES;	7	16^b b ppm of tin, determined by ICP-AES;	6
	1	5^b b ppm of tin, determined by ICP-AES;	3	7^b b ppm of tin, determined by ICP-AES;	6	5^b b ppm of tin, determined by ICP-AES;	5
	2	4^b b ppm of tin, determined by ICP-AES;	1	3^b b ppm of tin, determined by ICP-AES;	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^b b ppm of tin, determined by ICP-AES; ,^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.
	3	3^b b ppm of tin, determined by ICP-AES;	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	2^b b ppm of tin, determined by ICP-AES;	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^b b ppm of tin, determined by ICP-AES; ,^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.
	4	0^b b ppm of tin, determined by ICP-AES; ,^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^b b ppm of tin, determined by ICP-AES; ,^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^b b ppm of tin, determined by ICP-AES; ,^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.	0^c c below the limit of quantification (LOQ). LOQCd = 0.00972 ppm; LOQSn = 1.53 ppm; LOQFe = 0.0277 ppm.

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