ebook img

Ultra trace analysis and mobility of palladium emissions from automotive catalytic converters PDF

159 Pages·2017·11.07 MB·English
by  
Save to my drive
Quick download
Download
Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.

Preview Ultra trace analysis and mobility of palladium emissions from automotive catalytic converters

Ultra trace analysis and mobility of palladium emissions from automotive catalytic converters - Dissertation - zur Erlangung des Doktorgrades Dr. rer. nat. der Fakultät für Naturwissenschaften der Universität Ulm vorgelegt von Roland Schindl aus Garmisch-Partenkirchen Ulm, März 2015 Amtierender Dekan: Prof. Dr. Joachim Ankerhold Erstgutachter: Prof. Dr. Kerstin Leopold Zweitgutachter: Prof. Dr. Mika Lindén Tag der Promotion: 07. Juli 2015 Für meine Eltern Contents List of Figures v List of Tables ix List of Abbreviations xi 1. Zusammenfassung 1 2. Abstract 6 3. Information about palladium 10 3.1. Supply and demand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2. Application in and emission from automotive catalytic converters . 11 3.3. Distribution and toxicity of palladium . . . . . . . . . . . . . . . . . . 13 4. Applied analytical techniques 17 4.1. Microwave-assisted digestion . . . . . . . . . . . . . . . . . . . . . . . 17 4.2. Flow injection analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.3. High-resolution continuum source graphite furnace atomic absorp- tion spectrometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.4. Total X-ray reflection fluorescence spectroscopy . . . . . . . . . . . . 21 4.5. Transmission electron microscopy . . . . . . . . . . . . . . . . . . . . . 23 5. Determination of palladium traces in complex matrices 25 5.1. Methods for the determination of palladium traces . . . . . . . . . . 25 5.1.1. Microwave-assisted digestion of palladium-containing envi- ronmental samples . . . . . . . . . . . . . . . . . . . . . . . . . 25 – i – CONTENTS 5.1.2. Pre-concentrationandseparationtechniquesfortraceamounts of palladium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.1.3. Techniques for palladium trace detection . . . . . . . . . . . . 30 5.2. Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 5.2.1. Development of a microwave-assisted digestion procedure . 34 5.2.2. Development of pre-concentration and separation procedure 35 5.2.3. Validation of the analytical procedure . . . . . . . . . . . . . . 43 5.2.4. Analytical figures of merit . . . . . . . . . . . . . . . . . . . . . 50 5.2.5. Investigation of road tunnel dust samples . . . . . . . . . . . 52 5.2.6. Investigation of roadside soil samples . . . . . . . . . . . . . . 56 5.3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 5.4. Experimental procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 63 5.4.1. Sample collection . . . . . . . . . . . . . . . . . . . . . . . . . . 63 5.4.2. Pre-treatment of samples . . . . . . . . . . . . . . . . . . . . . 64 5.4.3. Microwave-assisted digestion procedures . . . . . . . . . . . . 64 5.4.4. Matrix characterization . . . . . . . . . . . . . . . . . . . . . . 66 5.4.5. Setup of the FIAS . . . . . . . . . . . . . . . . . . . . . . . . . . 66 5.4.6. Programming with LabVIEW . . . . . . . . . . . . . . . . . . . 68 5.4.7. HR-CS-GF-AAS measurement . . . . . . . . . . . . . . . . . . 70 5.4.8. Recovery rate of palladium in soil . . . . . . . . . . . . . . . . 71 5.4.9. Validation with road tunnel dust BCR-723 . . . . . . . . . . . 71 5.4.10. Determination of the Pd content in road tunnel dusts . . . . 71 5.4.11. Determination of the Pd content in roadside soil samples . . 72 5.4.12. Cleaning of vessels . . . . . . . . . . . . . . . . . . . . . . . . . 72 5.4.13. Preparation of dilutions for calibrations . . . . . . . . . . . . 72 5.4.14. Cleaning of digestion vessels . . . . . . . . . . . . . . . . . . . 73 5.4.15. Cleaning and preparation of the TXRF quartz glass carriers 73 6. Mobility and solubility of palladium 74 6.1. Presentstateofknowledgeonthemobilityandsolubilityofpalladium 74 6.2. Mobility of palladium in water-saturated porous media . . . . . . . . 76 6.2.1. Characterization of the model columns . . . . . . . . . . . . . 76 6.2.2. Breakthrough curves of the columns . . . . . . . . . . . . . . 77 – ii – CONTENTS 6.3. Dissolution rate of metallic palladium in the presence of small com- plexing agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 6.4. Conclusions and outlook. . . . . . . . . . . . . . . . . . . . . . . . . . . 88 6.5. Experimental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 6.5.1. Preparation of model columns . . . . . . . . . . . . . . . . . . 89 6.5.2. Determination of the pore volume and flow rate. . . . . . . . 89 6.5.3. General procedure for migration experiments . . . . . . . . . 89 6.5.4. Measurement of the concentrations . . . . . . . . . . . . . . . 90 6.5.5. Dissolution experiments . . . . . . . . . . . . . . . . . . . . . . 90 7. Synthesis of palladium and platinum nanoparticles 91 7.1. Definition of nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.2. Strategies for the synthesis of metal nanoparticles. . . . . . . . . . . 93 7.3. State-of-the-art of bottom-up syntheses of Pd and Pt nanoparticles . 96 7.4. Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 7.4.1. 4 nm-sized citric acid-coated palladium nanoparticles . . . . 97 7.4.2. 10 nm-sized non-coated palladium nanoparticles . . . . . . . 99 7.4.3. 8 nm-sized citric acid-coated palladium nanoparticles . . . . 101 7.4.4. 8 nm-sized citric acid-coated platinum nanoparticles . . . . . 103 7.4.5. Characteristics of the aqueous colloidal nanoparticle solutions104 7.5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 7.6. Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 7.7. Experimental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 7.7.1. Synthesis of palladium nanoparticles . . . . . . . . . . . . . . 108 7.7.2. Synthesis of platinum nanoparticles. . . . . . . . . . . . . . . 109 7.7.3. TEM measurements . . . . . . . . . . . . . . . . . . . . . . . . 111 7.7.4. Measurementofthepalladiumandplatinumconcentrations of the colloidal nanoparticle solutions . . . . . . . . . . . . . . 111 8. Applied statistics 113 8.1. Mean and standard deviation . . . . . . . . . . . . . . . . . . . . . . . 113 8.2. Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 – iii – CONTENTS 8.3. Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 8.3.1. Recovery function . . . . . . . . . . . . . . . . . . . . . . . . . . 116 8.3.2. Reference materials . . . . . . . . . . . . . . . . . . . . . . . . 117 Bibliography 118 Appendices A. List of equipment, instruments and software 131 B. List of chemicals 134 C. Danksagung 136 D. Curriculum vitae 138 E. List of publications 141 F. Eidesstattliche Erklärung 143 – iv – List of Figures 3.1. Global palladium demand of several industries in percentage from 1990 until 2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2. Schematic view of an automotive catalytic converter. . . . . . . . . . 12 4.1. Schematic of a classical flow injection system. . . . . . . . . . . . . . 18 4.2. Principles of a) X-ray fluorescence and b) the Auger effect.. . . . . . 22 4.3. Schematic view of a TXRF setup. . . . . . . . . . . . . . . . . . . . . . 23 4.4. Schematic of a transmission electron microscope. . . . . . . . . . . . 24 5.1. The chemical structure of (N, N)-diethyl-(N’)-benzoylthiourea . . . 29 5.2. Complexation of Pd(II) with DEBT. . . . . . . . . . . . . . . . . . . . 30 5.3. A) Schematic of the FIAS in the load and elution position. B) Schematic of the FIAS in the sample transfer position. . . . . . . . . 36 5.4. Parts of the self-made microcolumn: a) body housing, b) microcol- umn, c) membrane, d) graphite sample carrier for HR-CS-GF-AAS measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 5.5. Influence of the elution volume on the absorbance signal tested by applicationof4.0mLofapalladiumstandardsolutionof200ngL−1. Error bars represent the standard deviation (N=3).. . . . . . . . . . 41 5.6. Influence of the sample loop volumes on the absorbance signal. A palladium standard solution of 50 ng L−1 was used. Error bars derive from the standard deviation (N=3). The linear regression is shown in gray (R2 = 0.9943). . . . . . . . . . . . . . . . . . . . . . . . 42 5.7. Results of the TXRF measurements of the loess loam soil sample. . 44 – v – LIST OF FIGURES 5.8. Exemplary HR-CS-GFAAS spectrum of a loess loam soil sample spiked with 300 ng kg−1 Pd after FIAS separation and pre-concen- tration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 5.9. Recovery function obtained for Pd-spiked loess loam soil (y=1.01· x−5.94, R2 =0.9570). measurement data (black), red line: linear regression, green lines: confidence intervals, with P=95%, N=3. . . 47 5.10. Results of the TXRF measurements of BCR-723. . . . . . . . . . . . 49 5.11. Linear working range of the FIAS/HR-CS-GF-AAS method from 9.74 to 500 ng Pd L−1. Black: measurement data, red line: linear regression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 5.12. ResultsoftheTXRFmeasurementsoftheroadtunneldusts. Green bars: Eselsberg tunnel, red bars: Bismarckring tunnel, blue bars: Trappentreu tunnel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 5.13. Palladium demands and palladium contents in the dust sample of the Trappentreu tunnel . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5.14. a) Profile of the infiltration basin at the sampling site next to mo- torway A7 with the sampling rows A, B and C. b) Top view of the sampling site next to the A7 motorway indicating the individual sampling spots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 5.15. Mean values for elements detected in roadside soil samples from the A7 motorway by TXRF measurements. . . . . . . . . . . . . . . . 58 5.16. Front panel of the LabVIEW program. . . . . . . . . . . . . . . . . . 69 5.17. Schematic diagram of the created LabVIEW program. . . . . . . . . 70 6.1. Schematic of a model column. . . . . . . . . . . . . . . . . . . . . . . . 77 6.2. Migration of ionic Pd(II) (black), citrate-coated Pd NPs (blue) and non-coated Pd NPs (red) in a) silica, b) sand and c) potting soil. The Pd in the effluent is given as the ratio between the measured mass (m) and the initially applied mass (m ). Error bars represent 0 ± one standard deviation obtained from three individual column experiments and threefold measurement of each fraction (N=9). . . 78 – vi – LIST OF FIGURES 6.3. Cumulated amount of ionic Pd(II) (black), citrate-coated Pd NPs (blue) and non-coated Pd NPs (red) in the effluent from a) silica, b) sand and c) potting soil columns. The Pd in the effluent is given as the ratio between the measured mass (m) and the initially applied mass (m ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 0 6.4. Concentration of dissolved Pd black in the presence of EDTA plot- tedagainstthereactiontimeof309daysinseconds. Measurement datawereobtainedfromthreeindividualbatchescoloredblack,red and blue. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 6.5. ConcentrationofdissolvedPdblackinthepresenceofL-methionine plotted against the reaction time of 251 days in seconds. Mea- surementdatawereobtainedfromthreeindividualbatchescolored black, red and blue. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 6.6. Linear fit (black line) to the increasing Pd concentrations of the first 24 days ([Pd] = 4.74 · 10−6 [mol L−1] + x · 5.60 · 10−12 [mol s−1 L−1], R2 = 0.8971). Measurement data were obtained from three individual batches colored black, red, and blue. Green lines: confi- dence intervals with N=18, P=95%. . . . . . . . . . . . . . . . . . . . 85 6.7. Linear fit (black line) to the increasing Pd concentrations of the first 24 days ([Pd] = 3.99 · 10−6 [mol L−1] + x · 8.08 · 10−12 [mol s−1 L−1], R2 = 0.9866). Measurement data were obtained from three individual batches colored black, red and blue. Green lines: confi- dence intervals with N=12, P=95%. . . . . . . . . . . . . . . . . . . . 86 7.1. Schematic of different coatings of nanoparticles . . . . . . . . . . . . 93 7.2. Schematic of the bottom-up and top-down method. . . . . . . . . . . 94 7.3. a) TEM image of the 4 nm-sized citric acid-coated Pd NPs. b) His- togram of the size distribution of the 4 nm-sized citric acid-coated Pd NPs (N=1044). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 7.4. a) TEM image of the 10 nm-sized non-coated Pd NPs. b) His- togram of the size distribution of the 10 nm-sized non-coated Pd NPs (N=502). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 – vii –

Description:
Schematic view of an automotive catalytic converter 12 tern des Instituts für Analytische und Bioanalytische Chemie bedanken, nämlich.
See more

The list of books you might like

Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.