Publications by Christian Ludwig

Pt/Ce x Zr1-x O2 Bi-Functional Catalyst for Gas Recombination and Radical Scavenging in PEM Water Electrolysis Cells

Incorporating platinum (Pt) as a gas recombination catalyst in proton exchange membranes (PEMs) effectively addresses the challenge of pronounced hydrogen crossover in PEM water electrolysis cells, particularly when thin membranes are employed. However, th ...

AMER CHEMICAL SOC2025

Characterization of Biobased Polymers at the Gas-Solid Interface─Analysis of Surface and Bulk Properties during Artificial Degradation

Christian Ludwig, Jeremy Luterbacher, Michel Rossi, Tobias Borgmeyer

Accurately assessing the interfacial composition and reactivity of (bio)polymers under controlled but environmentally relevant conditions remains challenging. This study explores the evolution of surface functionalities of novel polyesters Poly(Butylene Xy ...

2025

Purification of Cellulose and Chitin Polymers and Other Value-Added Products from the Microalga Chlorella vulgaris Using a Green Biorefinery Process

Christian Ludwig, Horst Pick, Enio Daniel Zanchetta, Eya Nicodeme

Microalgae produce renewable biomass at high efficiency by using photosynthesis to capture the greenhouse gas CO2 from the atmosphere and releasing O2. Chlorella vulgaris is one of the most frequently cultivated unicellular green microalgae of commercial r ...

2025

Carbon-supported ZnO materials for sulfur capturing in supercritical water

Christian Ludwig, Andrea Testino

Sulfur (S) capturing materials working at supercritical water (SCW) conditions need to be designed and developed to overcome issues related with catalyst poisoning during the hydrothermal gasification of wet biomass, an efficient and sustainable technology ...

2025

From proof to practice − Sampling and analysis for simplified quantification of siloxanes in biogas

Christian Ludwig, Hossein Madi

Siloxanes in biogas pose significant challenges to energy systems, leading to operational inefficiencies and increased maintenance costs. This study advances the liquid quench sampling system (LQ) for accurate quantification of siloxanes using gas chromato ...

Elsevier2025

Recycling rare earth metals from luminescent fibers by solvent extraction

Christian Ludwig, Ajay Bhagwan Patil

Rare earth elements (REEs) are known for their specialized optical and electronic properties that have led to their use in a wide range of applications, such as luminescent fibers employed in security papers (e.g., bank notes). Most of the security documen ...

Elsevier BV2025

An Aerogel-Based Light-Driven Knudsen Pump Approaching Complete Passive Capturing of Airborne Particles in Wide Size Ranges

Christian Ludwig, Tianyu Cen

Aerosol sampling stands as an essential step in air quality monitoring and characterization. Active sampling provides accurate aerosol determination, while passive sampling offers cost-effective and power supply-free design. However, passive sampling is su ...

Elsevier BV2025

Abiotic stress approaches for enhancing cellulose and chitin production in Chlorella vulgaris

Christian Ludwig, Horst Pick, Enio Daniel Zanchetta, Eya Nicodeme

Several lines of evidence point to the presence of both, cellulose and chitin as structural constituents of the Chlorella vulgaris cell wall. These biopolymers are favourable building blocks for many sustainable industrial applications for instance as bioc ...

Elsevier BV2025

Continuous Supercritical Water Impregnation Method for the Preparation of Metal Oxide on Activated Carbon Composite Materials

Christian Ludwig

Metal oxide (MexOy) nanomaterials are used as catalysts and/or sorbents in processes taking place in supercritical water (scH2O), which is the “green” solvent needed to obtain energy-relevant products. Their properties are significantly influenced by the s ...

2024

Revealing the role of land-use features on macrolitter distribution in Swiss freshwaters

Christian Ludwig

Macrolitter, especially macroplastics, (> 0.5 cm) negatively impact freshwater ecosystems, where they can be retained along lake shores, riverbanks, floodplains or bed sediments. Long-term and large-scale assessments of macrolitter on riverbanks and lake s ...

Elsevier BV2024