604
time-on-stream study (up to 5 h) of all catalysts. Promoted catalysts showed a promising activity when compared to the unpromoted catalyst. Especially, Ca-promoted
catalyst maintained greater than 95% conversion throughout the 5-h time-on-stream
study. This behaviour of the catalyst is attributed to higher thermal stability of Ni
due to stronger metal support interaction. Different promoters (Zr, La and Ce) with
Co-based SBA-15-supported catalysts were utilized for SRG by Carrero et al. [98].
Promoted catalysts gave nearly 100% glycerol conversion than unpromoted catalyst
at 600 °C. They observed that Co crystal size obtained from XRD for the promoted
catalyst was less than that of unpromoted catalyst. So, low crystal size particles
were easy to reduce. This was the main reason of superior catalytic activity of promoted catalysts. Recently, Al-Salihi et al. [99] investigated the catalyst activity
based on a time-on-stream study at 650 °C. All the catalysts showed glycerol conversion in the range of 90–100% except for Ni-SBA-15 catalyst (Fig. 4). Bimetallic
catalyst maintained complete conversion, and no sign of deactivation of catalysts
was observed during the reaction period of 40 h. Ni-SBA-15 catalyst yielded 85%
conversion, and it slowly dropped to 10% at the end of reaction. Addition of MgO
Table 5 N 2 adsorption-desorption data of different mesoporous supported catalysts
Catalysts
Metals
(wt%)
BET surface
area (m
2 /g)
Average pore
diameter (nm)
Pore volume
(cc/g)
References
SBA-15
–
581
8.7
1.00
[97]
Ni/SBA-15
Ni (6.8)
545
8.3
0.91
[97]
Ni/Mg/SBA-15 Ni (6.7)
Mg (6.0)
313
7.4
0.62
[97]
Ni/Ca/SBA-15
Ni (6.5)
Ca (7.1)
291
7.3
0.58
[97]
SBA-15
–
581
8.7
1.00
[98]
Co/SBA-15
Co (7)
539
8.2
0.86
[98]
Co/Zr/SBA-15
Co (7)
Zr (8.5)
458
7.9
0.72
[98]
Co/Ce/SBA-15 Co (7)
Ce (8.5)
478
7.8
0.73
[98]
Co/La/SBA-15 Co (7)
La (8.5)
421
7.8
0.69
[98]
SBA-15
–
703.97
5.07
0.89
[99]
Co-Ni-SBA-15
(OP)
Ni (5)
Co (10)
706.57
4.89
0.68
[99]
Co-Ni-SBA-15
(IMPG)
Ni (5)
Co (10)
565.7
5.13
0.72
[99]
Al 2 O 3
–
188.3
8.1
0.66
[100]
Ni/Al 2 O 3
Ni (5)
183.5
8.75
0.53
[100]
Ni/Al 2 O 3
Ni (10)
176.6
8.0
0.47
[100]
Ni/Al 2 O 3
Ni (15)
158.3
7.8
0.39
[100]
Ni/Al 2 O 3
Ni (20)
143.3
7.4
0.36
[100]
S. Bepari et al.
time-on-stream study (up to 5 h) of all catalysts. Promoted catalysts showed a promising activity when compared to the unpromoted catalyst. Especially, Ca-promoted
catalyst maintained greater than 95% conversion throughout the 5-h time-on-stream
study. This behaviour of the catalyst is attributed to higher thermal stability of Ni
due to stronger metal support interaction. Different promoters (Zr, La and Ce) with
Co-based SBA-15-supported catalysts were utilized for SRG by Carrero et al. [98].
Promoted catalysts gave nearly 100% glycerol conversion than unpromoted catalyst
at 600 °C. They observed that Co crystal size obtained from XRD for the promoted
catalyst was less than that of unpromoted catalyst. So, low crystal size particles
were easy to reduce. This was the main reason of superior catalytic activity of promoted catalysts. Recently, Al-Salihi et al. [99] investigated the catalyst activity
based on a time-on-stream study at 650 °C. All the catalysts showed glycerol conversion in the range of 90–100% except for Ni-SBA-15 catalyst (Fig. 4). Bimetallic
catalyst maintained complete conversion, and no sign of deactivation of catalysts
was observed during the reaction period of 40 h. Ni-SBA-15 catalyst yielded 85%
conversion, and it slowly dropped to 10% at the end of reaction. Addition of MgO
Table 5 N 2 adsorption-desorption data of different mesoporous supported catalysts
Catalysts
Metals
(wt%)
BET surface
area (m
2 /g)
Average pore
diameter (nm)
Pore volume
(cc/g)
References
SBA-15
–
581
8.7
1.00
[97]
Ni/SBA-15
Ni (6.8)
545
8.3
0.91
[97]
Ni/Mg/SBA-15 Ni (6.7)
Mg (6.0)
313
7.4
0.62
[97]
Ni/Ca/SBA-15
Ni (6.5)
Ca (7.1)
291
7.3
0.58
[97]
SBA-15
–
581
8.7
1.00
[98]
Co/SBA-15
Co (7)
539
8.2
0.86
[98]
Co/Zr/SBA-15
Co (7)
Zr (8.5)
458
7.9
0.72
[98]
Co/Ce/SBA-15 Co (7)
Ce (8.5)
478
7.8
0.73
[98]
Co/La/SBA-15 Co (7)
La (8.5)
421
7.8
0.69
[98]
SBA-15
–
703.97
5.07
0.89
[99]
Co-Ni-SBA-15
(OP)
Ni (5)
Co (10)
706.57
4.89
0.68
[99]
Co-Ni-SBA-15
(IMPG)
Ni (5)
Co (10)
565.7
5.13
0.72
[99]
Al 2 O 3
–
188.3
8.1
0.66
[100]
Ni/Al 2 O 3
Ni (5)
183.5
8.75
0.53
[100]
Ni/Al 2 O 3
Ni (10)
176.6
8.0
0.47
[100]
Ni/Al 2 O 3
Ni (15)
158.3
7.8
0.39
[100]
Ni/Al 2 O 3
Ni (20)
143.3
7.4
0.36
[100]
S. Bepari et al.