Syzygy Plasmonics ($106M for photocatalyst reactors to produce fuels)

Syzygy Plasmonics is a deep-decarbonization company that builds all-electric chemical reactors using light instead of heat to power cleaner and safer chemical manufacturing. The company has raised $106 million in total funding and its photocatalytic reactor aims to revolutionize the industrial gas, chemical, and energy industries.

Challenges: industrial chemical production

Thermal catalysis is responsible for the production of approximately 85% of all industry-produced chemicals. However, thermal catalysis typically requires relatively extreme reaction conditions, such as high temperatures and pressures, resulting in reduced process efficiency and a substantial carbon footprint. Photocatalysis can drive chemical reactions under light illumination and requires a significantly lower temperature than thermal catalysts. In particular, plasmonic photocatalysts can drive chemical reactions with high photocatalytic efficiency, selectivity, and specificity, which is useful in carbon dioxide (CO₂) reduction and hydrogen gas (H₂) production.

However, it is difficult to design efficient photochemical reactor systems for industrial chemical production. Photocatalytic systems are primarily studied in academia at present.

Syzygy Plasmonics Technology

Syzygy Plasmonics designs and commercializes photocatalyst reactors that use renewable energy-powered light sources and plasmonic photocatalyst beds to drive chemical reactions at a low temperature. This light-driven chemical reactor allows the construction of the reactor with relatively inexpensive materials, such as glass or aluminum, and extends the lifespan of reactor components. In addition, Syzygy Plasmonics’s reactors are small and can be installed on-site to produce only the required amount of gas, eliminating the need for liquifying, transporting, and re-gasifying the liquid.

What are plasmonic photocatalysts?

Plasmonic photocatalysts are an emerging class of materials with the potential to significantly improve photocatalytic processes’ efficiency. They are made up of a combination of a plasmonic nanoparticle and photocatalysts. As shown in the figure below, each plasmonic photocatalyst consists of many tiny catalysts embedded on the surface of a larger plasmonic nanoparticle.

Plasmonic photocatalysts (Source: Syzygy Plasmonics).

Plasmonic nanoparticles are metallic nanoparticles “antennas” that interact strongly with light. As schematically depicted in the figure below, localized surface plasmon resonance (LSPR) enables a metal nanoparticle to harvest the light energy by concentrating it near the nanoparticle surface and then converting the light energy into excited charge carriers and heat. Catalysts used these energetic charge carriers and heat to drive chemical reactions on their surface.

The mechanism of chemical reactions driven by a plasmonic photocatalyst.

Plasmonic photocatalysts drive chemical reactions at low temperatures with high photocatalytic efficiency, selectivity, and specificity. In contrast, conventional thermal catalysts require a high temperature to drive heterogeneous catalytic reactions, which demands high energy inputs, shortens catalyst lifetimes, and requires selectivity to prevent unfavorable side reactions. Plasmonic photocatalysts are more advantageous and useful for specific industrial applications such as carbon dioxide (CO₂) reduction and hydrogen gas (H₂) production.

The material for plasmonic nanoparticles can consist of gold, gold alloy, silver, silver alloy, copper, copper alloy, aluminum, or aluminum alloy. The surface of plasmonic nanoparticles typically has an ultra thin layer of oxide film formed upon the nanoparticle’s exposure to air or water. For example, a copper plasmonic nanoparticle has a copper oxide (e.g., CuO or Cu₂O) shell surrounding the copper core, whereas an aluminum plasmonic nanoparticle has an aluminum oxide shell surrounding the aluminum core. The oxide shell can also be produced artificially using the appropriate chemical processes.

The catalyst material includes palladium, platinum, ruthenium, rhodium, nickel, iron, copper, cobalt, iridium, osmium, titanium, vanadium, indium, or any combination thereof. The catalyst may be intermetallic nanoparticles, core-shell nanoparticles, or semiconductor nanoparticles (e.g., Cu₂O).

Photocatalytic reactor

Syzygy Plasmonics designs and commercializes the plasmonic photocatalysts reactors such that the plasmonic photocatalysts are uniformly illuminated by light, thereby driving chemical reactions of reactant gas with high photocatalytic efficiency, selectivity, and specificity for industrial chemical production. The photocatalytic reactor is annular, with a nanoparticle photocatalyst packed bed. The cross section of an annular reactor is schematically depicted in the figure below.

Schematic diagram of Syzygy Plasmonics's photocatalyst reactor (ref. WO2022251704A1). — Schematic diagram of Syzygy Plasmonics’s photocatalyst reactor (ref. WO2022251704A1).

The annular region is hermetically sealed by top and bottom covers. The top and bottom seal covers are equipped with inlets for feed gas and outlets for product gas, respectively. The plasmonic photocatalyst packed bed is placed in the annular volume, leaving the upper reactor chamber empty for mixing the feeding gas flow. A porous base filter is placed beneath the catalyst bed, allowing gaseous products to flow through while remaining impermeable to the photocatalyst bed.

The annular region is made of materials that are visible and near IR transparent. The outer and inner walls of the annular region are mounted with light sources, so that both sides of the photocatalyst packed bed are illuminated to provide energy for the chemical reactions. The inner and outer cooling blocks serve to extend the life of the light sources by cooling them.

The catalyst packed bed contains catalyst support that has a low absorbance and desired transmittance, so that the plasmonic photocatalysts are exposed to sufficient irradiation for chemical reactions to occur. The catalyst support may be a suitable aerogel, such as including silicon dioxide aerogel, aluminum oxide aerogel, and titanium dioxide aerogel. The plasmonic photocatalysts are embedded into the aerogel.

Light sources, such as Light Emitting Diodes (LEDs) or IR lamps, can be powered by electricity produced from renewable resources, such as solar-, hydro-, or wind-generated power. Consequently, environmental benefits may be realized for industrial chemical reactions.

The diagram below depicts the working mechanism of the plasmonic photocatalyst reactor.

The reactant gasses are introduced into the annular region via the top cover inlets. In the upper portion of the annular reactor, gasses are mixed and then flow into the catalyst bed. Under light illumination, the plasmonic photocatalysts in the bed drive the conversion of reactant gasses into product gasses. Through the porous base filter, gasses exit the bed, and then the gasses exit the reactor through the bottom cover outlets.

The reactor can serve as a platform for multiple gas-phase chemical reactions that require high enthalpy of reaction and high activation energy, such as steam methane reforming and dry methane reforming for producing syngas, ammonia synthesis for the storage of hydrogen gas, and ammonia decomposition for the production of hydrogen gas.

Syzygy Plasmonics Patent

WO2022251704A1 Reactor cell for photocatalysis of gaseous species for industrial chemical production
WO2022020400A1 Methane reformer for the production of hydrogen and a hydrocarbon fuel
US20210339220A1 Photocatalytic Reactor System
WO2020146799A1 Optically transparent reactor cells for plasmonic photocatalytic chemical reactions using artificial light
JP2022174096A 複数の光触媒リアクタセルを有する光触媒リアクタ
IL271702A Photocatalytic reactor cell
PH12019550295A1 Photocatalytic reactor cell
CA3067808A1 Photocatalytic reactor having multiple photocatalytic reactor cells
US20210178377A1 Photocatalytic reactor cell
BR112019027906A2 Sistema reator fotocatalítico e método para transformar reagente
AU2018290768C1 Photocatalytic reactor cell
CN111032212A 光催化反应器单元
EP3645162A4 Photocatalytic reactor cell
NZ760120A Photocatalytic reactor cell
RU2761897C2 Photocatalytic reactor containing several photocatalytic elements
SG11201913211SA Photocatalytic reactor cell
MX2019015570A Photocatalytic reactor cell
KR102344738B1 다수의 광촉매 반응기 셀을 갖는 광촉매 반응기

Syzygy Plasmonics Products

The image below shows Syzygy Plasmonics’s Rigel photocatalytic reactor. This reactor provides the catalysts with superior light concentration and exposure, thereby facilitating highly efficient chemical reactions. The reactor is compact, comparable in size to a large washing machine or a small refrigerator.

Syzygy Plasmonics’s Rigel photocatalytic reactor (Source: Syzygy Plasmonics).

As shown in the figure below, banks of these reactors can be stacked to offer various installation sizes ranging from 1 ton per day to 100 tons or more per day.

A stack of Syzygy Plasmonics’s Rigel photocatalytic reactors for large scale production (Source: Syzygy Plasmonics).

The reactor is a platform for performing various chemical reactions by simply switching the photocatalyst bed and feeds. The same reactor can be used to produce hydrogen, steam methane reforming, dry methane reforming, and ammonia synthesis.

Syzygy Plasmonics Funding

Syzygy Plasmonics has raised a total of $106M in funding over 6 rounds, including a Seed round, two Grant rounds, a Series A round, a Series B round, and a Series C round. Their latest funding was raised on Nov 16, 2022 from a Series C round.