October 21
@
4:00 PM
–
5:00 PM
Önder Metin
College of Sciences, Koç University
Istanbul, Türkiye
Rational Design of Nano(photo)Catalysts for Green and Sustainable Chemical Conversions
Catalysts are central to numerous industrial processes, including fuel synthesis, polymer production, and pharmaceutical manufacturing, enabling reactions to proceed under milder conditions, with lower energy requirements, and with better selectivity by minimizing undesirable byproducts. Over the last quarter century, transition metal nanoparticles (NPs) have emerged as highly effective catalysts due to their large surface-to-volume ratio and the enhanced reactivity of surface atoms compared to bulk metals. These properties have enabled the rapid advancement of nanocatalysis, which often offers superior performance compared to traditional homogeneous and heterogeneous catalysts. Bimetallic NPs, either alloys or core-shell structures, are particularly important, as they often exhibit enhanced catalytic activity, selectivity, and stability due to synergistic interactions between two-distinct component metals. This approach is particularly useful for combining noble and non-noble metals, reducing cost without sacrificing efficiency.
In parallel, aligning catalytic strategies with green chemistry principles has motivated efforts to integrate photocatalysts capable of harvesting a broad spectrum of the solar spectrum. Such systems offer a sustainable route to more efficient and cost-effective chemical transformations. While semiconductor-based photocatalysts have long been under investigation, their widespread application is limited by challenges such as poor band-edge alignment with target reactions and rapid recombination of photogenerated charge carriers, both of which significantly reduce photocatalytic efficiency.
In this talk, I will highlight our rational approach to synthesizing monodisperse monometallic and bimetallic NPs, including alloy and core-shell structures supported on two-dimensional materials such as high-surface-area carbon or reduced graphene oxide (rGO) and mesoporous graphitic carbon nitride (mpg-CN). The rationale behind support selection will also be discussed. I will also describe the rational design of g-CN and other 2D semiconductor-based photocatalysts for various chemical transformations. The catalytic performance of these nanomaterials will be demonstrated in applications such as hydrogen production from chemical hydrogen storage materials (water, ammonia borane, and formic acid), transfer hydrogenation for the synthesis of valuable organic molecules under mild conditions, C–H bond functionalization, and electrochemical processes including CO₂ reduction and fuel-cell reactions. Finally, I will share insights from our experience commercializing an rGO–Ni₃₀Pd₇₀ nanocatalyst and a bismuthene photocatalyst for practical chemical transformations.