Highly Efficient Catalysis of Preferential Oxidation of CO in H₂-Rich Stream by Gold Single-Atom Catalysts

Abstract

Preferential oxidation of CO (PROX) in H2-rich stream is critical to the production of clean H2 for the H2-based fuel cells, which provide clean and efficient energy conversion. Development of highly active and selective PROX catalysts is highly desirable but proved to be extremely challenging. Here we report that CeO2-supported Au single atoms (Au1/CeO2) are highly active, selective, and extremely stable for PROX at the PEMFC working temperature (∼80 °C) with >99.5% CO conversion over a wide temperature window, 70–120 °C (or 50–100 °C, depending on the Au loading). The high CO conversion realized at high temperatures is attributed to the unique property of single-atom catalysts that is unable to dissociatively adsorb H2 and thus has a low reactivity toward H2 oxidation. This strategy is proven in general and can be extended to other oxide-supported Au atoms (e.g., Au1/FeO x ), which may open a new window for the efficient catalysis of the PROX reaction.

Evolution from the plasmon to exciton state in ligand-protected atomically precise gold nanoparticles

“…The difference of our results from Goodman's work can be attributed to the different morphologies of particles, that is, quasi-spherical particles in our work versus planar (for example, two atomic layer thick) gold particles in Goodman's work42. The calculated turnover frequency of Au 144 is 2 s −1 , which is comparable to the best catalysts reported43. Interestingly, the size trend in the electrocatalytic oxidation of alcohol (Fig.…”

Highly active and sintering-resistant heteroepitaxy of Au nanoparticles on ZnO nanowires for CO oxidation

“…Among these factors, however, the size of Au NPs might be the most critical: it is generally accepted by now that there is an optimum size range of 0.5-5 nm for CO oxidation. Recent experiments and theoretical calculations, however, have exclusively demonstrated that oxide supported Au single atoms can be extremely active, even better than the small Au clusters and NPs [65,68,69] . As a consequence, the control of the size and size distributions of supported Au NPs and the improvement of their sintering resistance are critical for developing practical supported Au NPs catalysts.…”

Novel mechanistic view of catalytic ozonation of gaseous toluene by dual-site kinetic modelling

“…The presence of Mn-O-C confirms that the active sites of graphene and the dispersed MnO 2 are strongly connected on the surface, thereby confirming the dual-site mechanism. In this mechanism, the two sites must be located sufficiently close to the surface to allow their adsorbed species to easily react with one other [50][51][52].…”