New insights into the role of hydrogen in cosmic silicon carbide synthesis
In this work, we investigate the formation mechanisms of silicon carbide cosmic dust under conditions mimicking the atmospheres of evolved carbon-rich stars. By combining ultra-high vacuum experiments, advanced spectroscopy and microscopy techniques, and theoretical modelling, we demonstrate the key role played by molecular hydrogen in triggering the chemical pathways that…
Formation of the Au2Sn alloy driven by hydrogen etching of β-SnSe/Au(111)
In this work, we present a novel methodology to transform the metal monochalcogenide (MMC) β-SnSe into the surface alloy Au2Sn through exposure to atomic hydrogen, which promotes selenium desorption from the surface. We have charactertized the transformation by means of STM, XPS and LEED, identifying an intermediate state where both…
Moiré-Induced Enhanced Hydrogen Adsorption on Graphene
Tailoring the adsorption properties of 2D materials for targeted chemical processes is a central challenge in surface science. In particular, modulating hydrogen binding on graphene has strong relevance for catalysis and energy applications. In this study, we investigate hydrogen chemisorption across ten distinct moiré superstructures formed by graphene on various…
On-surface synthesis of metal-organic oligomers from photoactive BOPHY molecules and native adatoms
Synthesizing new low-dimensional materials with tailored functionalities for specific applications remains a major challenge in the field of on-surface synthesis. Among these materials, polymers incorporating photoactive moieties stand out as promising candidates for photocatalytic applications, given the exceptional photocatalytic activity exhibited by their bulk counterparts. In this work, following an…
Concavity vs convexity: what is the role of molecular configuration on the reaction pathway?
The role of stereochemistry—the spatial arrangement of atoms within molecules—on the reaction pathway has been largely overlooked in on-surface synthesis despite being crucial in organic chemistry. In this work, we demonstrate how the starting diastereomeric configuration can drive the surface-induced transformation of a substituted cyclooctatetraene (COT) structure—a key molecule in…
New TERS with nanometer spatial resolution in ESISNA
We have designed and upgraded a scanning probe microscope (SPM) to allocate the required internal optical setup required to perform atomic-scale spectromicroscopy. This system is the first operational SPM-TERS in Spain capable of working under cryogenic and ultra-high vacuum (UHV) conditions with nanometre resolution. Unlike previous versions that rely on…
Design and Synthesis of a 2D Cu-Coordinated Carbon Nitride Network: A Promising Single-Atom Catalyst for Environmental Applications
Metal-coordinated networks are promising catalysts for environmental applications like green hydrogen production and pollutant photo-degradation. While traditionally 3D, recent efforts have extended these networks to 2D, though synthesis and stability remain challenging. Using a bottom-up approach, we successfully designed and synthesized a 2D hexagonal carbon nitride Cu-coordinated network by combining…
Gas-Phase Synthesis of n-Alkanes in Circumstellar Environments
Aliphatics are prevalent in various solar system bodies and the interstellar medium, with linear alkanes (n-CnH2n+2) detected in carbonaceous chondrites in small amounts. Despite their consistent presence, their formation mechanism in meteorites remains unclear. This study proposes a gas-phase synthesis mechanism for n-alkanes from carbon and hydrogen under conditions similar…
Front cover in ACS Catalysis
This study investigates sulfite ion electrooxidation in an alkaline environment using cyclic voltammetry on copper oxide electrodes with different oxidation states (Cu(I) and Cu(II)) and similar active areas. Nanostructured Cu films made of nanoparticles or nanorods were synthesized on glassy carbon electrodes. The findings reveal that Cu(I) electrodes demonstrate higher…
UV-Induced Mechanism of Aliphatic Cleavage in the Interstellar Medium
In the interstellar medium (ISM), UV processing leads to significant chemical transformations in hydrocarbons. Aliphatic hydrocarbons such as alkanes, commonly formed in evolved stars, undergo dehydrogenation primarily through UV-induced photocleavage of C–C bonds rather than direct hydrogen elimination. This study combines experimental data and ab initio calculations to understand how…