Supporting Information

In Situ Generated Platinum Catalyst for Methanol

Oxidation via Electrochemical Oxidation of

Bis(trifluoromethylsulfonyl)imide Anion in Ionic

Liquids at Anaerobic Condition

Yongan Tang, Zhe Wang, Xiaowei Chi, Michael D. Sevilla, and Xiangqun Zeng*

*Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States.

*E-mail: zeng@oakland.edu, Ph: 248-370-2881 (X.Z.)

Figure S1. (a) Multiple CV cycles at different potential ranges (a) -1.8 ~ 1.0 V, (b) -1.8 ~ 1.4 V,

(c) -1.8 ~ 1.6 V, and (d) -0.6 ~ 1.6 V of [Bmpy][NTf2] ionic liquid in nitrogen environment at Pt

electrode. Scan rate: 100 mV s-1

.

Figure S2. (a) Third cycle CVs of different scan rates in [Bmpy][NTf2] ionic liquid in nitrogen

environment at Pt electrode. Plots of peak current vs different scan rates, (b) first cycle, (c)

second cycle, (d) third cycle.

Figure S3. (a) CVs at different potential windows in [Bmpy][NTf2] ionic liquid in nitrogen

environment at Pt electrode. Scan rate: 100 mV s-1

; (b) Charge plot obtained from current of

peak II in (a). The 50th cycle of CV curve was presented (a) and analyzed (b).

Figure S4. CVs at different positive potential limits in [Bmpy][NTf2] ionic liquid in nitrogen

environment at Au electrode. Scan rate: 100 mV s-1

.

Figure S5. FT-IR spectra of [Bmpy][NTf2] during CV cycling process in nitrogen environment

Figure S6. (a) EQCM results at Pt QCM electrode in [Bmpy[[NTf2] as electrolyte and in N2

environment. Scan rate: 500 mV s−1. Black solid line: cyclic voltammetric response recorded by

potentiostat. Dashed blue line: mass change recorded by QCM. (b) Mass change versus the

number of the electron transferred curve in (a) after thirty cycles confirming the adsorption of

NTf2 radical on platinum surface by slope value. The slope (i.e. the ratio of Δm/Q (the change of

mass/charge)) after stable value (the 30th

cycle) is 280±10 g/mol. This value is consistent with

the molecular weight of NTf2 ion (280.3 g/mol) and suggests that the NTf2• radical formed due

to the oxidation of the anion of NTf2- results in the NTf2• neutral radical formation. The NTf2•

neutral radical is suggested to interact with Pt to form a Pt-NTf2• surface layer, which results in

the mass change.

Figure S7. Multiple cyclic voltammetry in [Bmpy][NTf2] ionic liquid, nitrogen environment at Pt

electrode; scan rate: 100 mV s-1

;

Figure S8. Multiple cyclic voltammetry cycles in [Bmpy][NTf2] ionic liquid in air environment.

Scan rate: 100 mV s-1

.

Table S1. The names and structures of ionic liquids used in this work

Anion Cation

NTf2

Bmpy

BF4

Bmim

Figure S9. Multiple CV cycles of 0.64% (v/v) methanol in [Bmim][BF4] ionic liquid in nitrogen

environment at Pt electrode; scan rate: 100 mV s-1

Figure S10. (a) Different scan rates of CV for 1.280% (v/v) methanol in [Bmpy][NTf2] ionic

liquid, (b) anodic and cathodic peak current vs. scan rate1/2

in (a).