Supplementary Material
Resolving Ruthenium: XPS Studies of Common Ruthenium Materials
David J. Morgan
Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Park Place, Cardiff.
CF10 3AT
Corresponding author: MorganDJ3@cardiff.ac.uk
Sample purity was determined using a combination of XRD (PANalytical X’Pert Pro
diffractometer fitted with a monochromatic Cu Kα source (λ = 0.154 nm) operated at 40 keV
and 40 mA) and FTIR spectroscopy (Varian 3100 Excalibur FTIR spectrometer with Varian
Resolutions Pro software).
The majority of samples proved to be X-ray amorphous and/or IR-invisible, the latter due to
their black colour. Additionally the highly hydroscopic nature of many of the samples (e.g.
RuCl3) resulted in changes in the hydration levels of the samples due to the air-based analytical
techniques used.
Regardless XRD reveals an amorphous phase for hydrated RuO2 whilst the anhydrous form
exhibits exclusively its rutile structure. RuCl3 XRD rapidly reacted with the atmosphere,
becoming very wet resulting again in an amorphous trace (not shown). Equally RuCl3 showed
no discernible IR-active bands other than water; additionally any potential Ru-Cl vibrational
modes are ca. 300 – 350 cm-1, below the limits of the instrument.
FTIR analysis of Ru(NO)(NO3)3 and Ru(AcAc) revealed strong bands expected for NO/NO3
in such nitrosyl compounds and C-H/C-O/C=O modes for acetylacetonates, the strongest bands
of which are detailed below.
Compound
Ru(NO)(NO3)3
Ru(AcAc)
Wavenumber / cm-1
1869
1506
1259
966
3001
2970
2926
1514
1421
1360
1269
1014
935
779
Assignment
(NO) & (NO3) modes[1 – 4]
(CH3)as
(CH3)as
(CH3)s
(C=C=C)
(CH3)s
(CH3) + (C=O)
(C=C=C)s
Q(CH3)s
(C-CH3)
(C-H)
Thermogravimetric analysis (TGA) of the RuO2 samples was performed using a Perkin Elmer
TGA 4000. All experiments were performed under nitrogen with 3-8 mg of oxide in each
experiment
Figure S1. TGA of the ruthenium oxides under flowing nitrogen with 10 °C min-1 ramp rate.
(a)
(b)
(c)
(d)
Figure S2. Fitted Ru(3p) spectra for a) RuO2 (anhydrous and hydrated), b) Ru(NO)(NO3)3, c)
Ru(acac)3 and d) RuCl3 (anhydrous and hydrated). Fitting parameters and discussion of the
peaks are given in the main paper.
Table S1. Spectral fitting parameters for O(1s) species recorded at 20 eV from this work.
Peak1
(eV)
%
FWHM
529.28
73.46
0.77
529.61
56.28
1.45
Ru(NO)(NO3)3
531.51
18.31
1.84
RuCl3
531.98
42.85
1.63
Compound
RuO2
(Anhydrous)
RuO2
(Hydrated)
Lineshape
LF(0.25,1,
45,280)
LF(0.9,1.2
,25,280)
LF(0.9,1.2
,25,280)
Peak2
(eV)
FWH
M
%
530.88
1.23
20.46
530.83
1.29
43.72
532.58
1.75
61.02
533.53
1.64
57.15
References
[1] Steed & Tocher, Polyhedron, 1994, 13 (2), pp 167-173.
[2] Rose & Mascharak, Inorg. Chem., 2009, 48 (14), pp 6904–6917.
[3] Videal et al. Inorg. Chem., 2006, 45 (21), pp 8608–861
[4] Shahroosvand et al., Dalton Trans., 2014, 43, pp 5158-5167
Lineshape
LF(0.25,1,
45,280)
LF(0.9,1.2
,25,280)
LF(0.9,1.2
,25,280)
Peak3
(eV)
FWHM
%
Lineshape
532.33
2.70
6.08
GL(30)
532.64
1.77
20.67
LF(0.9,1.2
,25,280)