Erratum: Selective adsorption of manganese onto rhodium for optimized Mn/Rh/SiO2 alcohol synthesis catalysts (ChemCatChem (2009) 1 (36653672))

Full text of DOI:10.1002/cctc.201402391

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CORRIGENDUM
J. Liu, R. Tao, Z. Guo, J. R. Regalbuto,
C. L. Marshall, R. F. Klie, J. T. Miller,
R. J. Meyer*
The authors would like to correct a mistake made in the calculation of the TOF num-
bers presented in Table 2. The corrected values provided here include a correction to
the original calculation in Table 2 regarding the gas flow rate (resulting in a substan-
tial change in the calculated TOF) and an additional correction based on CO chemi-
sorption experiments (as opposed to using a hemispherical model for the surface
area based on the TEM measurements). The results of the chemisorption experiments
are reported in Table S1 based on a 1:1 CO/Rh stoichiometry and indicate that the
dispersions of the three catalyst samples are quite similar. CO chemisorption meas-
urements were performed at the CleanCat Core facility at Northwestern University by
using an Altamira Instruments BenchCAT 1000HP. Catalysts (0.2–0.3 g) were loaded
into a U-shaped quartz reactor tube, which was weighed before and after sample ad-
dition to ensure an accurate weight measurement. This tube was then loaded into
the furnace. Each catalyst was reduced at 3008C for 2 h (108CminÀ1 ramp rate), then
flushed for 30 min in He. 5%CO/He was then pulsed (595 mL loop volume) into the
system 15–20 times at 308C to ensure the surface was saturated. Each spectrum was
integrated to find the volume of CO remaining following adsorption. Surface satura-
tion was typically reached within 10 pulses. The authors would like to thank Neil
Schweitzer of the Center for Catalysis and Surface Science, Northwestern University,
Illinois and David Childers of the University of Illinois at Chicago for their help with
the chemisorption measurements.
Selective Adsorption of Manganese
onto Rhodium for Optimized Mn/Rh/
SiO2 Alcohol Synthesis Catalysts
ChemCatChem 2013, 5, 3665–3672
DOI 10.1002/cctc.201300479
Although the chemisorption measurements indicate a lower dispersion for the incipi-
ent wetness impregnation (IWI)-prepared sample than may be supposed based on
particle size, the Mn promoter likely blocks some sites for CO adsorption if IWI is the
technique used for promotion addition. The corrected result does indicate that the
samples synthesized by IWI have slightly higher TOFs than those synthesized by
using strong electrostatic adsorption (SEA). However, the original paper focuses on
the differences in selectivity, therefore, the correction does not influence the conclu-
sions of the original paper.
In addition, the authors wish to correct an error in Figure 7. The edge position of the
Rh2O3 standard was misaligned and has been fixed, in agreement with existing litera-
ture.[1] A new version of Figure 7 is provided below. The correction does not change
the assignment of the state of Rh in the Mn-promoted Rh/SiO2 catalysts.
We wish to thank the anonymous reviewer (of a more recent paper on RhMn/C
nanotubes),[2] who pointed out our errors.
AHCTUNGTRENNUNG
[1] M. R. Gogate, R. J. Davis, ChemCatChem 2009, 1, 295–303.
[2] J. J. Liu, Z. Guo, D. Childers, N. Schweitzer, C. L. Marshall, R. F. Klie, J. T. Miller, R. J.
Meyer, Journal of Catalysis 2014, 313, 149–158.
ꢀ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemCatChem 14, 6, 1806 – 1818 1817

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Table 2. Conversion of syngas over promoted and unpromoted Rh cata-
lysts supported on silica.
Catalyst
CO conv.[a]
[%]
TOF[b]
[sÀ1
E[a,c]
[%]
A[a,d]
[%]
M[a,e]
[%]
L[a,f]
[%]
O[a,g]
[%]
G
]
3%Rh/SiO2
1%MnSEA
3%Rh/SiO2
4.3
6.8
8.3
11.0
13.2
18.2
24.5
36.4
45.0
7.5
0.012
0.068
0.064
0.070
0.061
0.067
0.068
0.067
0.063
0.081
0.077
0.079
0.075
0.079
0.085
0.087
–
–
30
70
4.8
5.8
6.6
6.4
6.0
6.8
1.8
1.6
51.2
49.2
50.6
46.5
46.9
28.9
18.8
–
19.1
18.0
18.0
20.4
17.8
17.8
14.6
14.3
4.8
5.3
4.5
5.8
6.0
15.2
12.5
10.0
8.7
7.1
5.0
3.3
3.9
8.4
8.4
7.5
7.6
7.6
3.6
2.5
41.0
40.3
44.1
37.0
42.5
47.3
52.3
50.2
17.5
19.9
20.6
23.6
23.2
16.7
20.5
20.0
23.6
21.9
27.6
26.6
23.0
25.0
18.1
18.1
17.3
16.9
16.6
16.4
33.0
28.5
1%MnIWI
3%Rh/SiO2
8.8
10.8
14.5
19.0
27.0
42.0
5.6
5.0
[a] The CO conversions were calculated by using nitrogen gas as the inter-
nal standard and the equation:
CO Conversion [%]=(MCO feedÀMN feed/MN product MCOproduct)/MCOfeed 100%
2
2
in which Mi is the mole percent of component i. The selectivity to product
i is based on the total number of carbon atoms among the total products
and is defined as:
Selectivityi [%]=(ni Mi)/ACTHNURGTNEGNU(Sni Mi)100%
in which ni is the number of carbon atoms, and Mi is the mole percent of
product i detected downstream. [b] The TOF is calculated as CO conver-
sion per site per second. The dispersion of Rh particles was determined
by using CO chemisorption (1:1 CO/Rh site). [c] Selectivity for ethanol;
[d] Selectivity for acetaldehyde; [e] Selectivity for methane; [f] Selectivity
for light hydrocarbons C3+ ; [g] Selectivity for acetic acids and C3+ oxygen-
ates.
Table S1. Dispersion of catalysts measured by CO chemisorption.
Catalyst
Dispersion
[%]
1%MnSEA3%Rh/SiO2
1%MnIWI3Rh/SiO2
3%Rh/SiO2
57.1
50.8
50.1
Figure 7. XANES spectrum of Rh K-edge of 1 wt% Mn promoted 3 wt% Rh/
SiO2 catalysts plotted with appropriate standards: Rh2O3 reference (a),
1%MnSEA3%Rh/SiO2 catalyst (c), 1%MnIWI3%Rh/SiO2 catalyst (c), 3%Rh/
SiO2 catalyst (c), and Rh foil reference (c).
ꢀ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemCatChem 14, 6, 1806 – 1818 1818