Evaluation of transition metal phosphides supported on ordered mesoporous materials as catalysts for phenol hydrodeoxygenation. Issue 7 (10th December 2015)

• Record Type: Journal Article
• Authors: Berenguer, A.; Sankaranarayanan, T. M.; Gómez, G.; Moreno, I.; Coronado, J. M.; Pizarro, P.; Serrano, D. P.
• Is Part Of: Green chemistry. Volume 18:Issue 7(2016)
• Page Start: 1938
• Page End: 1951
• Publication Date: 2015-12-10
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c5gc02188j
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Transition metal phosphides (Ni2 P, Co2 P and MoP) supported over mesoporous materials: Al-SBA-15, m-Al2 O3 and CMK-3 have been probed as potential catalysts in HDO of pyrolysis bio-oils using phenol as model compound. Abstract : A series of transition metal phosphides (Ni2 P, Co2 P and MoP) have been synthesized by temperature programmed reduction of the corresponding metal phosphate precursors loaded over mesostructured Al-SBA-15, mesoporous γ-Al2 O3 (m-Al2 O3 ) and ordered mesoporous carbon (CMK-3). Both the dispersion and metal phosphide phases attained are strongly influenced by the support features, such as their acidic and textural properties. XRD, TEM and H2 chemisorption results revealed that the MoP phase was probably formed but it underwent a fast re-oxidation in air. On the other hand, metal phosphide formation was hindered over m-Al2 O3 as only metallic Ni and Co were detected. All the materials prepared have been evaluated as catalysts in hydrodeoxygenation (HDO) using phenol as a bio-oil model compound. The highest phenol conversions were attained with the catalysts based on the acidic supports (Al-SBA-15 and m-Al2 O3 ). Nevertheless, Co2 P/Al-SBA-15, Ni2 P/m-Al2 O3 and Co2 P/m-Al2 O3 yielded cyclohexanol as the main product denoting very low HDO efficiency. In contrast, Ni2 P/Al-SBA-15 showed remarkable catalytic properties, being the only catalyst that provided almost full phenol conversion and extremely high HDO efficiency, with cyclohexane selectivity higher than 90%. This may be due to a synergetic effect between the high electron deficiency, generated by the Ni α + (0 < α < 1) species owing to an electron transfer from Ni to P and the different acidic sites present in the catalyst.