Metal carbide-based catalyst systems for plastic recycling

A method for catalytic hydrogenolysis of a polymer comprising:

• a) activating a catalyst with a hydrogen source to provide an activated catalyst, wherein the catalyst comprises:
• i) a MXene support of Formula I:
• Mn+1XnTx (I);
• wherein each M is independently an early transition metal;
• X is carbon or nitrogen;
• Tx is a surface functional group wherein x is 0-10;
• and n is 1, 2, 3, or 4;
• and
• ii) a supported metal, wherein atoms of the supported metal occupy crystal lattice nodes at the basal plane of the MXene support, the atoms of the supported metal are supported by metallic bonding to the early transition metal, the supported metal has one to five nanostructured layers of its atoms on the MXene support, and loading of the supported metal on the MXene support is less than 5% w/w based on the weight of the catalyst;
• and
• b) contacting a mixture of the activated catalyst, hydrogen gas, and a polymer at a temperature of at least about 200° C., optionally in the presence of an inert gas, for a period of time that is sufficient for catalytic hydrogenolysis of the polymer;
• thereby converting the polymer to a fuel.

A method for catalytic hydrogenolysis of a polyolefin comprising:

• a) activating a catalyst by heating the catalyst in the presence of hydrogen gas to provide an activated catalyst, wherein the catalyst comprises:
• i) a MXene support represented by Formula (II) or Formula (III):
• Mo2TiC2Tx (II);
• W2TiC2Tx (III);
• wherein Tx is a surface functional group wherein x is 0-10;
• and
• ii) copper metal, wherein atoms of the copper metal occupy crystal lattice nodes at the basal plane of the MXene support, the atoms of the copper metal are supported by metallic bonding to molybdenum or tungsten atoms of the MXene support, the copper metal has one to five nanostructured layers of its atoms on the MXene support, and loading of the copper metal on the MXene support is less than 2% w/w based on the weight of the catalyst;
• and
• b) contacting a mixture of the activated catalyst, hydrogen gas, and a polyolefin at a temperature of at least about 200° C. for a period of time that is sufficient for catalytic hydrogenolysis of the polyolefin;
• thereby converting the polyolefin to a fuel.