The analytical tools to quantify CO₂RR products are often slow and have high limits of detection. As a result, researchers are forced to extend the duration of their experiments to accumulate sufficient product and surpass these detection limits. This slows down research considerably, and the research scope often remains limited. To help speed up CO₂RR catalyst studies, we have developed a new differential electrochemical mass spectrometer (DEMS) setup and cell design that enables the quantification of major gaseous and liquid products significantly faster than conventional analytical techniques. Special attention was given to the hydrodynamics of the cell to avoid mass transfer limitations and the calibration of the setup to accurately quantify the major CO₂ reduction products. As proof of concept of the methodology, the products formed during CO₂RR on a polycrystalline Ag and Cu electrode in a 0.1-M KHCO₃ electrolyte at different potentials were measured and quantified.

Currently commercial NO_x removal (DeNO_x) abatement systems for lean-burn engines exceed regulation limits on the road for NO_x emissions. Commercial DeNO_x catalysts exhibit poor performance in the selective conversion of NO to N₂, especially at high temperature and high gas hourly space velocities (GHSV). In this study, oxygen vacancies of reduced ceria and Pt/ or Rh/ceria are found to be the efficient and selective catalytic sites for NO reduction to N₂. Even at low concentrations, NO can compete with an excess of O₂ at 600 °C and a high GHSV of 170 000 L L⁻¹ h⁻¹, conditions in which SCR and NSR DeNO_x system are not able to function well. N₂O is not detected over the whole range of conditions, whereas NO₂ is only formed upon oxidation of the catalyst, after both NO and O₂ start to appear. For consideration of the fuel economy, the working temperature should be between 250 and 600 °C. Above 600 °C, most of the injected fuel was combusted with O₂. Below 250 °C, ceria support will not be reduced by fuel and the oxidation rate of the deposited carbon through oxygen from ceria lattice will be too low.