Mo Li | EPFL Graph Search

Born in 1988 in Shenyang, China, Mo Li graduated with a BSc and MSc in Chemical Engineering from Dalian University of Technology in 2012 and 2015, respectively. During this time, he worked on projects on membranes for gas separation and the synthesis of well-defined nanostructure. He then went on to pursue PhD studies in ETH Zurich in 2015 working on CO2 sorbents and metal-oxide gas sensors. In 2017, he moved to EPFL and continued with his PhD focusing on near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) for the investigation of CO2 hydrogenation mechanisms.

High-Throughput Sizing, Counting, and Elemental Analysis of Anisotropic Multimetallic Nanoparticles with Single-Particle Inductively Coupled Plasma Mass Spectrometry

Ayush Agarwal, Natalia Gasilova, Cedric David Koolen, Mo Li, Wen Luo, Andreas Züttel

Nanoparticles (NPs) have wide applications in physical and chemical processes, and their individual properties (e.g., shape, size, and composition) and ensemble properties (e.g., distribution and homogeneity) can significantly affect the performance. However, the extrapolation of information from a single particle to the ensemble remains a challenge due to the lack of suitable techniques. Herein, we report a high-throughput single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS)-based protocol to simultaneously determine the size, count, and elemental makeup of several thousands of (an)isotropic NPs independent of composition, size, shape, and dispersing medium with atomistic precision in a matter of minutes. By introducing highly diluted nebulized aqueous dispersions of NPs directly into the plasma torch of an ICP-MS instrument, individual NPs are atomized and ionized, resulting in ion plumes that can be registered by the mass analyzer. Our proposed protocol includes a phase transfer step for NPs synthesized in organic media, which are otherwise incompatible with ICP-MS instruments, and a modeling tool that extends the measurement of particle morphologies beyond spherical to include cubes, truncated octahedra, and tetrahedra, exemplified by anisotropic Cu NPs. Finally, we demonstrate the versatility of our method by studying the doping of bulk-dilute (

2022

Support-Dependent Cu-In Bimetallic Catalysts for Tailoring the Activity of Reverse Water Gas Shift Reaction

Youngdon Ko, Mo Li, Wen Luo, Thi Ha My Pham, Kun Zhao, Liping Zhong

Cu-based bimetallic catalysts have attracted great attention for the reverse water gas shift (RWGS) reaction due to their high activity and selectivity. This work reports the application of Cu-In bimetallic catalysts for the RWGS reaction and demonstrates that the promotion effect of In on Cu is support sensitive. The Cu-In/ZrO2 catalyst exhibited significantly higher CO2 conversion than the Cu/ZrO2 catalyst, whereas the CO2 conversion over Cu-In/CeO2 was much lower than that of Cu/CeO2. The reasons of the support-dependent RWGS activity was revealed by systematic characterizations. On the ZrO2 support, Cu and In formed Cu-In alloys and promoted the activation of CO2 by the oxygen vacancies from partially reduced In2O3. On the CeO2 support, Cu and In were in the form of metallic Cu and In2O3, respectively. The dispersion of Cu and the formation of oxygen vacancies on CeO2 were obstructed by the introduction of In, leading to decreased RWGS activity. Among these catalysts, Cu/CeO2 showed the best RWGS activity because of the strong CO2 activation ability of the partially reduced CeO2 support and the highly active Cu/CeO2-x interfaces. These results provide new insights into the design and understanding of supported bimetallic catalysts for CO2 hydrogenation.

AMER CHEMICAL SOC2022

Tandem effect of Ag@C@Cu catalysts enhances ethanol selectivity for electrochemical CO2 reduction in flow reactors

Youngdon Ko, Cedric David Koolen, Mo Li, Wen Luo, Thi Ha My Pham, Jie Zhang, Liping Zhong, Andreas Züttel

CO-selective metals (e.g., Ag) on Cu catalysts improve the selec-tivity of multi-carbon (C2+) products in electrochemical CO2 reduc-tion. However, the origin of the improvement remains unclear due to the convolution of tandem and interface effects. Here, Ag@C@Cu core-shell catalysts were synthesized, in which the thin carbon interlayer inhibited the direct interaction between Ag and Cu while still allowing the reduction of CO2 on Ag, thus isolating the tandem effect from other effects. This catalyst produced higher ratios of ethanol to ethylene relative to the monometallic Cu catalyst, demonstrating that the locally increased CO concentration promoted the ethanol pathway over the ethylene pathway. Further, the selectivity of ethanol was optimized by tuning the thickness of the Cu shell. This work provides a rational approach to design core-shell catalysts for understanding structure-performance relationships and demonstrates the key role of the tandem effect in tuning the selectivity of C2+ products.

ELSEVIER2022